2nd CompMusic Workshop

Dates: July 12th-13th, 2012
Venue: Bahçeşehir Üniversitesi, Beşiktaş, Istanbul (Turkey)
Scientific Committee: Xavier Serra, Preeti Rao, Hema Murthy, Bariş Bozkurt


Workshop Program

July 11th Wednesday:

20:00h Folk makam music concert by Bengi Bağlama Üçlüsü (Fazıl Say Salonu, Bahçeşehir Üniversitesi)

July 12th Thursday:

09:30h Opportunities for a Cultural Specific Approach in the Computational Description of Music. Xavier Serra
10:10h Culture Specific Music Information Processing: A Perspective from Hindustani Music. Suvarnalata Rao
10:50h Tea break
11:20h Carnatic Music: Svara, Gamaka, Motif and Raga Identity. T M Krishna and Vignesh Ishwar
12:00h A Semiotic Approach to the Analysis of Makam Melodies: The Beginning Sections of Melodies as "Makam Indexes". Okan Murat Ozturk
12:40h Lunch
14:10h A Musically Aware System for Browsing and Interacting with Audio Music Collections. Mohamed Sordo, Gopala Krishna Koduri, Sertan Şentürk, Sankalp Gulati and Xavier Serra
14:30h Improving the Understanding of Turkish Makam Music through the MediaCycle Framework. Onur Babacan, Christian Frisson and Thierry Dutoit
14:50h The Concept of Çeşni and Computational Analysis of Performance-Theory Disparities in Turkish Music. Eren Özek
15:10h An Integrated Framework for Transcription, Modal and Motivic Analysis of Maqam Improvisation. Olivier Lartillot and Mondher Ayari
15:30h Tea break
16:00h A Unified System for Analysis and Representation of Indian Classical Music using Humdrum Syntax. Ajay Srinivasamurthy and Parag Chordia
16:20h Incorporating Features of Distribution and Progression for Automatic Makam Classification. Erdem Ünal, Bariş Bozkurt and M. Kemal Karaosmanoğlu
16:40h Analysis of the Folksonimy of Freesound. Frederic Font and Xavier Serra
17:00h A Method for Extracting Semantic Information from on-line Art Music Discussion Forums. Mohamed Sordo, Joan Serrà, Gopala Krishna Koduri and Xavier Serra
19:00h Dinner
20:00h Ottoman music concert directed by Bekir Reha Sağbaş (Fazıl Say Salonu, Bahçeşehir Üniversitesi)























July 13th Friday:

09:30h Features for Analysis of Makam Music. Bariş Bozkurt
09:50h Applause Identification and its Relevance to Archival of Carnatic Music. P. Sarala, Vignesh Ishwar, Ashwin Bellur and Hema A Murthy
10:10h Auditory Scene Analysis and the Performance and Perception of Tabla Rhythms in Hindustani Music. Punita G. Singh
10:30h A Beat Tracking Approach to Complete Description of Rhythm in Indian Classical Music. Ajay Srinivasamurthy, Sidharth Subramanian, Gregoire Tronel, Parag Chordia
10:50h Tea break
11:20h Metrical Strength and Contradiction in Turkish Makam Music. Andre Holzapfel and Bariş Bozkurt
11:40h Sculpting the Sound. Timbre-Shapers in Classical Hindustani Chordophones. Matthias Demoucron, Stéphanie Weisser and Marc Leman
12:00h Signal Analysis of Ney Performances. Tan Hakan Özaslan, Xavier Serra and Josep Lluis Arcos
12:20h An Approach for Linking Score and Audio Recordings in Makam Music of Turkey. Sertan Şentürk, André Holzapfel and Xavier Serra
12:40h Lunch
14:10h Generating Computer Music from Skeletal Notation for Carnatic Music Compositions. M. Subramanian
14:30h A Knowledge Based Signal Processing Approach to Tonic Identification in Indian Classical Music. Ashwin Bellur, Vignesh Ishwar, Xavier Serra and Hema Murthy
14:50h A Two-stage Approach for Tonic Identification in Indian Art Music. Sankalp Gulati, Justin Salamon and Xavier Serra
15:10h Characterization of Intonation in Karṇāṭaka Music by Parametrizing Context-based Svara Distributions. Gopala Krishna Koduri, Joan Serrà and Xavier Serra
15:30h Tea break
16:00h Detection of Raga-characteristic phrases from Hindustani Classical Music Audio. Joe Cheri Ross and Preeti Rao
16:20h Classification of Indian Classical Vocal Styles from Melodic Contours. Amruta Vidwans, Kaustuv Kanti Ganguli and Preeti Rao
16:40h A Two-Component Representation for Modeling Gamakas of Carnatic Music. Srikumar K. Subramanian, Lonce Wyse and Kevin McGee
17:00h Motivic Analysis and its Relevance to raga Identification in Carnatic Music. Vignesh Ishwar, Ashwin Bellur and Hema Murthy
























X. Serra: "Opportunities for a Cultural Specific Approach in the Computational Description of Music" [articleslides, video]
The current research in Music Information Retrieval (MIR) is showing the potential that the Information Technologies can have in music related applications. A major research challenge in that direction is how to automatically describe/annotate audio recordings and how to use the resulting descriptions to discover and appreciate music in new ways. But music is a complex phenomenon and the description of an audio recording has to deal with this complexity. For example, each music culture has specificities and emphasizes different musical and communication aspects, thus the musical recordings of each culture should be described differently. At the same time these cultural specificities give us the opportunity to pay attention to musical concepts and facets that, despite being present in most world musics, are not easily noticed by listeners. In this paper we present some of the work done in the CompMusic project, including ideas and specific examples on how to take advantage of the cultural specificities of different musical repertoires. We will use examples from the art music traditions of India, Turkey and China.

S. Rao: "Culture Specific Music Information Processing: A Perspective from Hindustani Music" [articleslides, video]
Music can be considered as an art and/or industry. Regardless of this dichotomy, the totality of any music tradition can be studied keeping in view the following ten aspects that are integral to every tradition: compose, perform, receive, perceive, teach, learn, preserve, access, disseminate & share. These areas are interdependent yet mutually influencing. In this paper I outline some issues that have either a direct or indirect bearing on these areas. My observations will be from a perspective of a practitioner and musicologist especially engaged in a project related to computational musicology. I will concentrate mainly on five aspects: listening, intonation, improvisation, instruments and notation. The paper also includes a short discussion of our research project AUTRIM (automated transcription system for Indian music), developed in collaboration with Prof. Wim van der Meer of University of Amsterdam.

T M Krishna and V. Ishwar: "Carnatic Music : Svara, Gamaka, Motif and Raga Identity" [article, slides, video]
Over the last century, in Karnatic music, the method of understanding raga has been, to break it down into its various components, svara, scale, gamaka and phrases. In this paper, an attempt is made to define the abstract concept of raga in its entirety, within the Karnatic aesthetic, considering the various factors and importantly, the symbiotic relationship between, svara, gamaka and phraseology. This paper also attempts to prove that the identity of a raga, exists as a whole. We first illustrate the concept of fundamental musical note or svara and we deal with the concept of gamaka or inflexions. We then discuss the concept of a raga and its identity in terms of svara, gamaka and phraseology. 

O. M. Ozturk: "A Semiotic Approach to the Analysis of Makam Melodies: The Beginning Sections of Melodies as "Makam Indexes"" [article, video]
The beginning part of makam melodies are one of the basic discriminating features of makams. The region on the scale where the melody begins seems to be an important feature for discriminating makams using especially the same intervallic order or scale. It appears that, to clarify the distinction of such makams (which use the same scale) within this context, a semiotics approach can contribute to better understanding of such characteristics. It is proposed here that performing an analytical study based on observation of melody initiation points and based on the concepts defined by C. S. Peirce (1839-1914) can lead to derivation of “makam indexes”. Via this approach, it could be possible to derive some features to capture that characteristic and further use it for computer based analysis of discriminating features of such makams.

M. Sordo, G. K. Koduri, S. Şentürk, S. Gulati and X. Serra: "A Musically Aware System for Browsing and Interacting with Audio Music Collections" [article, slides, video]
AbstractIn the context of the CompMusic project we are developing methods to automatically describe/annotate audio music recordings pertaining to various music cultures. As a way to demonstrate the usefulness of the methods we are also developing a system to browse and interact with specific audio collections. The system is an online web application that interfaces with all the data gathered (audio, scores plus contextual information) and all the descriptions that are automatically generated with the developed methods. In this paper we present the basic architecture of the proposed system, the types of data sources that it includes, and we mention some of the culture specific issues that we are working on for its development. The system is in a preliminary stage but it shows the potential that MIR technologies can have in browsing and interacting with music collections of various cultures.

O. Babacan, C. Frisson and T. Dutoit: "Improving the Understanding of Turkish Makam Music through the MediaCycle Framework" [article, video]
The goal of this work is to investigate the challenges of creating a tool to aid people of diverse profiles, from musicology experts and music information retrieval (MIR) specialists, to the interested non-technical users outside these fields in understanding traditional makam music of Turkey. We aim at providing a playground approach, with which MIR specialists can easily validate algorithms for feature extraction, clustering and visualization, and non-technical users can navigate by easily varying parameters and triggering audiovisual previews. We adapted the MediaCycle framework for organization of media files by similarity. AudioCycle, its audio application, allows users to cluster a large number of audio files against a subset of extracted audio features, visualized in a 2D space through positions, distances, colors. Transitions between parametric changes are animated, which helps the user create and retain a mental model of the sounds and their relationships. For our proof-of-concept, we defined our use case as detecting makamlar (plural) from makam music. We integrated the pitch histogram technique proposed by Bozkurt et. al as a feature extraction plugin in AudioCycle to meet this goal.

E. Özek: "The Concept of Çeşni and Computational Analysis of Performance-Theory Disparities in Turkish Music" [article, video]
Although there are some studies on the maqam theory in Turkish Music, there is an absence of a system, which is approved by all music authorities and establishes the unity between the theory and the performance. Therefore, the debates on these topics and research attempts for such a system have not been finalized. Within the frame of these attempts, the starting point should be thorough analysis of performances to eliminate the disparities between the theory and the performance. Accurate evaluation of the results of such analysis might leads to a theory that has roots from the performance and enable us to describe a system that is coherent with the performance. Thus, the technology should be utilized for the analysis of the audio recordings from well-known performers. In this work, au- dio recordings, which are recorded by the present day per- formers specifically for this research, and audio recordings from past masters are analyzed. The results of the analysis are demonstrated and compared to the theoretical values Holder comma values. The effects of the performance on the melodic structure are also investigated.

O. Lartillot and M. Ayari: "An Integrated Framework for Transcription, Modal and Motivic Analysis of Maqam Improvisation" [article, slidesvideo]
The CréMusCult project is dedicated to the study of oral/aural creativity in Mediterranean traditional cultures, and especially in Maqam music. Through a dialogue between anthropological survey, musical analysis and cognitive modeling, one main objective is to bring to light the psychological processes and interactive levels of cognitive processing underlying the perception of modal structures in Maqam improvisations. One current axis of research in this project is dedicated to the design of a comprehensive modeling of the analysis of maqam music founded on a complex interaction be-tween progressive bottom-up processes of transcription, modal analysis and motivic analysis and the impact of top-down influence of higher-level information on lower-level inferences. Another ongoing work attempts at formalizing the syn-tagmatic role of melodic ornamentation as a Retentional Syntagmatic Network (RSN) that models the connectivity between temporally closed notes. We propose a specifica-tion of those syntagmatic connections based on modal context. A computational implementation allows an au-tomation of motivic analysis that takes into account me-lodic transformations. The ethnomusicological impact of this model is under consideration. The model was first designed specifically for the analysis of a particular Tunisian Maqam, with the view to pro-gressively generalize to other maqamat and to other types of maqam/makam music.

A. Srinivasamurthy and P. Chordia: "A Unified System for Analysis and Representation of Indian Classical Music using Humdrum Syntax" [article, video]
Chordia proposed a new system for the analysis and representation of bandiṣes (bandishes) and gaṭs (gats) in Hindustani music using humdrum syntax (Frontiers of Research in Speech and Music Conference, 2007). In this paper, we extend the capabilities of this system to encode Carnatic music and propose a unified system for Indian classical music. It enables us to systematically encode Carnatic music compositions into a machine readable format. The **carnatic representation builds on the **bhat representation, with additional changes to incorporate the elements from Carnatic music such as gamakas, 16 śr̥ti, and a more complex tāla system. The linear text-based intermediate representation for data entry is also extended to encode additional metadata useful in Carnatic music. The representation system will be useful for symbolic music research, generation of synthetic melodies, and comparative analyses.

E. Ünal, B. Bozkurt and M. K. Karaosmanoğlu: "Incorporating Features of Distribution and Progression for Automatic Makam Classification" [article, slides, video]
Automatic classification of makams from symbolic data is a rarely studied topic. In this paper, first a review of an n-gram based approach is presented using various representations of the symbolic data. While a high degree of precision can be obtained, confusion happens mainly for makams using (almost) the same scale and pitch hierarchy but differ in overall melodic progression, seyir. To further improve the system, first n-gram based classification is tested for various sections of the piece to take into account a feature of the seyir that melodic progression starts in a certain region of the scale. In a second test, a hierarchical classification structure is designed which uses n-grams and seyir features in different levels to further improve the system.

F. Font and X. Serra: "Analysis of the Folksonomy of Freesound" [article, slides, video]
User generated content shared in online communities is often described using collaborative tagging systems where users assign labels to content resources. As a result, a folksonomy emerges that relates a number of tags with the resources they label and the users that have used them. In this paper we analyze the folksonomy of Freesound, an online audio clip sharing site which contains more than two million users and 150,000 user-contributed sound samples covering a wide variety of sounds. By following methodologies taken from similar studies, we compute some metrics that characterize the folksonomy both at the global level and at the tag level. In this manner, we are able to better understand the behavior of the folksonomy as a whole, and also obtain some indicators that can be used as metadata for describing tags themselves. We expect that such a methodology for characterizing folksonomies can be useful to support processes such as tag recommendation or automatic annotation of online resources.

M. Sordo, J. Serrà, G. K. Koduri and X. Serra: "A Method for Extracting Semantic Information from on-line Art Music Discussion Forums" [article, slides, video]
In this paper a method for extracting semantic information from online music discussion forums is proposed. The semantic relations are inferred from the co-occurrence of musical concepts in forum posts, using network analysis. The method starts by defining a dictionary of common music terms in an art music tradition. Then, it creates a complex network representation of the online forum by matching such dictionary against the forum posts. Once the complex network is built we can study different network measures, including node relevance, node co-occurrence and term relations via semantically connecting words. Moreover, we can detect communities of concepts inside the forum posts. The rationale is that some music terms are more related to each other than to other terms. All in all, this methodology allows us to obtain meaningful and relevant information from forum discussions.

B. Bozkurt: "Features for Analysis of Makam Music" [article, slides, video]
For computational studies of makam music, it is essential to gather a list of characteristics that constitute a makam and explore corresponding quantitative features for automatic analysis. This study is such an attempt where we address the characteristics for makams as defined in theory books and deduce a list of quantitative features. The target here is to evoke discussions on some measurable features other than providing complete analysis on the discriminative potentials of each proposed feature which could be the subject of a few larger studies.

P. Sarala, V. Ishwar, A. Bellur and H. Murthy: "Applause Identification and its Relevance to Archival of Carnatic Music" [article, slides, video]
A Carnatic music concert is made up of a sequence of pieces, where each piece corresponds to a particular genre and raaga (melody). Unlike a western music concert, the artist may be applauded intra-performance, inter-performance. Most Carnatic music that is archived today correspond to a single audio recordings of entire concerts. The purpose of this paper is to segment single audio recordings into a sequence of pieces using the characteristic features of applause and music. Spectral flux, spectral entropy change quite significantly from music to applause and vice-versa. The characteristics of these features for a subset of concerts was studied. A threshold based approach was used to segment the pieces into music fragments and applauses. Preliminary results on recordings 19 concerts from matched microphones show that the EER is about 17% for a resolution of 0.25 seconds. Further, a parameter called CUSUM is estimated for the applause regions. The CUSUM values determine the strength of the applause. The CUSUM is used to characterise the highlights of a concert.

P. G. Singh: "Auditory Scene Analysis and the Performance and Perception of Tabla Rhythms in Hindustani Music" [video]
The ‘bols’ used to construct rhythms in Hindustani tabla performance are onomatopoeic sounds differing in auditory attributes such as timbre and pitch. Simpler bols can be played simultaneously to create compound bols and sequential placement of such bols leads to the formation of rhythms. The systematic permutation and combination of bols generate recurring accent markers that contribute to the perceived metricality of a sequence.  Principles of Auditory Scene Analysis can help in understanding how metrical structure is established based on timbre similarities and differences. Strategies adopted by Hindustani musicians in reinforcing rhythms at different tempi can also be explained by phenomena such as stream segregation.  At slow speeds (vilambit laya), performers use filler sounds to maintain perceptual connectivity. At high speeds (drut laya) perceptual segregation of compound bols into simpler components creates layers that provide scaffolding that helps in maintaining a steady rhythm.  The lens of Auditory Scene Analysis is a productive way to view how the acoustic properties of different bols influence their interaction as a function of tempo.  It also offers insights about the strategic leveraging of such relations in tabla performance and the perception of emergent rhythms by listeners.

A. Srinivasamurthy, S. Subramanian, G. Tronel and P. Chordia: "A Beat Tracking Approach to Complete Description of Rhythm in Indian Classical Music" [article, video]
In this paper, we propose a beat tracking and beat similarity based approach to rhythm description in Indian Classical Music. We present an algorithm that uses a beat similarity matrix and inter onset interval histogram to automatically extract the sub-beat structure and the long-term periodicity of a musical piece. From this information, we can then obtain a rank ordered set of candidates for the tāla cycle period and the naḍe (sub-beat structure). The tempo, beat locations along with the tāla and naḍe candidates provide a better overall rhythm description of the musical piece. The algorithm is tested on a manually annotated Carnatic music dataset (CMDB) and Indian light classical music dataset (ILCMDB). The allowed metrical levels recognition accuracy of the algorithm on ILCMDB is 79.3% and 72.4% for the sub-beat structure and the tāla, respectively. The accuracy on the difficult CMDB was poorer with 68.6% and 51.1% for naḍe and tāla, respectively. The analysis of the algorithm's performance motivates us to explore knowledge based approaches to tāla recognition.

A. Holzapfel and B. Bozkurt: "Metrical Strength and Contradiction in Turkish Makam Music" [article, slides, video]
In this paper we investigate how note onsets in Turkish Makam music compositions are distributed, and in how far this distribution supports or contradicts the metrical structure of the pieces, the usul. We use MIDI data to derive the distributions in the form of onset histograms, and compare them with metrical weights that are applied to describe the usul in theory. We compute correlation and syncopation values to estimate the degrees of support and contradiction, respectively. While the concept of syncopation is rarely mentioned in the context of this music, we can gain interesting insight into the structure of a piece using such a measure. We show that metrical contradiction is systematically applied in some metrical structures. We will compare the differences between Western music and Turkish Makam music regarding metrical support and contradiction. Such a study can help avoiding pitfalls in later attempts to perform audio processing tasks such as beat tracking or rhythmic similarity measurements.

M. Demoucron, S. Weisser and M. Leman: "Sculpting the Sound. Timbre-Shapers in Classical Hindustani Chordophones" [article, video]
Chordophones of the contemporary classical Hindustani tradition are characterized by the presence of one or both of these two specific devices: the sympathetic strings taraf (from about 10 to over 30) and the curved wide bridge jawari (sometimes reinforced by a cotton thread). The influence of the taraf and jawari devices has been scarcely investigated, even though players consider both the taraf’s response and the jawari effect as fundamental to the instruments sound. Based on field recordings and interviews, this study aims to quantify the contribution of taraf strings and wide curved bridge jawari to the global sound of the different instruments and settings. Acoustical analyses are correlated with ethnomusicological analyses, in order to evaluate the tarafs and jawaris aesthetic, musical and perceptual role.

T. H. Özaslan, X. Serra and J. Ll. Arcos: "Signal Analysis of Ney Performances" [article, video]
Ney is an end-blown flute which is mainly used for Makam music. Although from the beginning of 20th century a score representation based on extending the Western music is used, because of its rich embellishment repertoire, actual Ney music can not be totally represented by written score. Ney is still taught and transmitted orally in Turkey. Because of that the performance has a distinct and important role in Ney music. Therefore signal analysis of ney performances is crucial for understanding the actual music. Another important aspect which is also a part of the performance is the articulations that performers apply. In Makam music in Turkey none of the articulaitons are taught even named by teachers. Articulations in Ney are valuable for understanding the real performance. Since articulations are not taught and their places are not marked in the score, the choice and character of the embellishment is unique for each performer which also makes each performance unique. Our method analyzes audio files of well known Turkish Ney players. In order to obtain our analysis data, we analyzed audio files 8 of different performers going from the 1920s to the year 2000.

S. Şentürk, A. Holzapfel and X. Serra: "An Approach for Linking Score and Audio Recordings in Makam Music of Turkey" [article, slides, video]
A music piece can be studied by using various information sources, especially symbolic scores and audio recordings. Since they are complementary representations, it is very useful to have a proper linking of the musically meaningful events in the piece. For the case of makam music in Turkey, linking symbolic notations and the corresponding audio recordings might require a specific approach due to the characteristics of the music such as different tunings and extensive usage of non-notated expressive elements. Moreover, for most of the pieces of the classical repertoire, there are different versions of scores rather than a single one written by the composer. This paper proposes a methodology to pair fragments of a score to the corresponding fragments of audio recording performances. Pitch information obtained from both sources is used as the common representation to be paired. From the audio recording, fundamental frequency estimation and tuning analysis is done to compute a pitch contour. From the score, symbolic note names and durations are converted to a synthetic pitch contour. Then, a soft-match is performed on these two pitch contours in order to find the best correspondences of these two representations. This methodology may give us a needed tool for computational tasks such as form analysis, audio-score alignment and makam recognition.

M. Subramanian: "Generating Computer Music from Skeletal Notation for Carnatic Music Compositions" [article, slides, slides+audio, video]
Although a high degree of improvisation is the hall mark of Carnatic music, it still revolves around compositions mostly written in the past 250 years. The music is carried down the generations by oral tradition. A composition may be preceded by or interspersed with improvisations.  Carnatic music notation uses the sol-fa  (sa ri ga ma pa da ni  for the 7 notes)  which is written on one line and the lyric on the next line. Books containing notation for Carnatic music compositions were printed in the 19th century and continue to be printed. The notation available in books is only skeletal and does not represent the music completely though many musicians can fill up the nuances intuitively. The objective of the present work is to generate acceptable music from the notation with the computer filling up for the gamakams and other require-ments. This paper describes the work done and under development.  The notation player Gaayaka uses the tra-ditional notation transliterated into English with slight modifications and can play acceptable music if the nuances are also notated but cannot automatically add nuances for which a separate program has been written.

A. Bellur, V. Ishwar, X. Serra and H. Murthy: "A Knowledge Based Signal Processing Approach to Tonic Identification in Indian Classical Music" [article, slides, video]
In this paper, we describe several techniques for detecting tonic pitch value in Indian classical music. In Indian music, the raga is the basic melodic framework and it is built on the tonic. Tonic detection is therefore fundamental for any melodic analysis in Indian classical music. This work explores detection of tonic by processing the pitch histograms of Indian classic music. Processing of pitch histograms using group delay functions and its ability to amplify certain traits of Indian music in the pitch histogram, is discussed. Three different strategies to detect tonic, namely, the concert method, the template matching and segmented histogram method are proposed. The concert method exploits the fact that the tonic is constant over a piece/concert. Template matching method and segmented histogram methods use the properties: (i) the tonic is always present in the background, (ii) some notes are less inflected and dominant, to detect the tonic of individual pieces. All the three methods yield good results for Carnatic music (90−100% accuracy), while for Hindustanimusic, the template method works best, provided the vadi samvadi notes for a given piece are known (85%).

S. Gulati, J. Salamon and X. Serra: "A Two-stage Approach for Tonic Identification in Indian Art Music" [article, slides, video]
In this paper we propose a new approach for tonic identification in Indian art music and present a proposal for a complete iterative system for the same. Our method splits the task of tonic pitch identification into two stages. In the first stage, which is applicable to both vocal and instrumental music, we perform a multi-pitch analysis of the audio signal to identify the tonic pitch-class. Multipitch analysis allows us to take advantage of the drone sound, which constantly reinforces the tonic. In the second stage we estimate the octave in which the tonic of the singer lies and is thus needed only for the vocal performances. We analyse the predominant melody sung by the lead performer in order to establish the tonic octave. Both stages are individually evaluated on a sizable music collection and are shown to obtain a good accuracy. We also discuss the types of errors made by the method. Further, we present a proposal for a system that aims to incrementally utilize all the available data, both audio and metadata in order to identify the tonic pitch. It produces a tonic estimate and a confidence value, and is iterative in nature. At each iteration, more data is fed into the system until the confidence value for the identified tonic is above a defined threshold. Rather than obtain high overall accuracy for our complete database, ultimately our goal is to develop a system which obtains very high accuracy on a subset of the database with maximum confidence.

G. K. Koduri, J. Serrà and X. Serra: "Characterization of Intonation in Karṇāṭaka Music by Parametrizing Context-based Svara Distributions" [article, slides, video]
Intonation is a fundamental music concept that has a special relevance in Indian art music. It is characteristic of the rāga and intrinsic to the musical expression of the performer. Describing intonation is of importance to several information retrieval tasks like the development of rāga and artist similarity measures. In our previous work, we proposed a compact representation of intonation based on the parametrization of the pitch histogram of a performance and demonstrated the usefulness of this representation through an explorative rāga recognition task in which we classified 42 vocal performances belonging to 3 rāgas using parameters of a single svara. In this paper, we extend this representation to employ context-based svara distributions, which are obtained with a different approach to find the pitches belonging to each svara. We quantitatively compare this method to our previous one, discuss the advantages, and the necessary melodic analysis to be carried out in future.

J. C. Ross and P. Rao: "Detection of Raga-characteristic phrases from Hindustani Classical Music Audio" [article, slides, video]
Melodic motifs form essential building blocks in Indian Classical music. The motifs, or key phrases, provide strong cues to the identity of the underlying raga in both Hindustani and Carnatic styles of Indian music. Automatic identification and clustering of similar motifs is relevant in this context. The inherent variations in various instances of a characteristic phrase in a bandish (composition) performance make it challenging to identify similar phrases in a performance. A nyas svara (long note) marks the ending of these phrases. The proposed method does segmentation of phrases through identification of nyas and computes similarity with the reference characteristic phrase.

A. Vidwans, K. K. Ganguli and P. Rao: "Classification of Indian Classical Vocal Styles from Melodic Contours" [article, slides, video]
A prominent categorization of Indian classical music is the Hindustani and Carnatic traditions, the two styles having evolved under distinctly different historical and cultural influences. Both styles are grounded in the melodic and rhythmic framework of raga and tala. The styles differ along dimensions such as instrumentation, aesthetics and voice production. In particular, Carnatic music is perceived as being more ornamented. The hypo-thesis that style distinctions are embedded in the melodic contour is validated via subjective classification tests. Melodic features representing the distinctive characteristics are extracted from the audio. Previous work based on the extent of stable pitch regions is supported by measurements of musicians’ annotations of stable notes. Further, a new feature is introduced that captures the presence of specific pitch modulations characteristic of orna-mentation in Indian classical music. The combined features show high classification accuracy on a database of vocal music of prominent artistes. The misclassifications are seen to match actual listener confusions.

S. K. Subramanian, L. Wyse and K. McGee: "A Two-Component Representation for Modeling Gamakas of Carnatic Music" [article, video]
Continuous pitch movements called “gamakas” are a prominent feature of Carnatic music, but are not included in its traditional notation system. Modeling the melodic and shape aspects of gamakas and how they are selected for phrases given as notation are interesting inter-related problems that have analogs in text to speech and expressive singing synthesis systems. Descriptive textual and graphical notation techniques have also been proposed as tools for studying gamakas. However, a concatenative model of phrase-level gamaka selection leads to a combinatorial explosion of possibilities to be selected from. We propose a “longest path” optimization algorithm for phrase-level selection of gamakas that solves this combinatorial explosion using a scoring function that expresses local continuity preferences; and a two-component “stage-dance” representation of gamakas which simplifies the scoring function by separating local melodic and shape continuity preferences. We analyzed a performance of a composition in this framework and found the approach to be able to imitate the phrase-level preferences exhibited by the performer.

V. Ishwar, A. Bellur and H. Murthy: "Motivic Analysis and its Relevance to raga Identification in Carnatic Music" [article, slides, video]
A raga is a collective melodic expression consisting of motifs. A raga can be identified using motifs which are unique to it. Motifs can be thought of as signature prosodic phrases. Different ragas may be composed of the same set of notes, or even phrases, but the prosody may be completely different. In this paper, an attempt is made to determine the characteristic motifs that enable identification of a raga and distinguish between them. To determine this, motifs are first manually marked for a set of five popular raga by a professional musician. The motifs are then normalised with respect to the tonic. HMMs are trained for each motif using 80% of the data and about 20% are used for testing. The results do indicate that about 80% of the motifs are identified as belonging to a specific raga accurately.