Quantitative Analysis of Phrasing Strategies in Expressive Performance:

Authors: Eric Cheng and Elaine Chew Year: 2008

Presentation by: Elvira Burdiel GalendeELEM021, Queen Mary University

19 March 2012

Computational Methods and Analysis of Performances of Unaccompanied Bach for Solo Violin

Introduction 1/2 Goal – Quantitative analysis of

phrasing strategies of expressive performance in violin. Andante movement from Bach’s Sonata

No.2 in A minor BWV 1003 for solo violin Regular pulse Unambiguous phrase structure

11 recorded performances + average Unlimited musician freedom on

expressive performance?

Introduction 2/2 Look for indicator of phrasing strategy:

Tempo extraction Loudness/dynamics extraction

Analysis of phrasing strategies via LMPD method Phrase strength - clarity Phrase volatility – variability of strength Phrase typicality – uniqueness of strategy

Tempo extraction Violin: soft indetermined onsets

No reliable and accurate automatic beat tracking tool

Manual onset detection using a digital waveform editor. Tempo = inverse of inter-onset interval Rectangular smoothing window

Dynamics extraction Use two existing models:

1- Single-band Leq (RLB) model 2- Multiband PEAQ loudness model Sample loudness at onsets Smooth by Gaussian window

Test models with manual annotation Correlation higher on 2 -> method

chosen

Extracted data Global means and ranges Section means and ranges

4 sections: A A’ B B’ Phrase means and ranges

Extracted data - global

Extract data – Section means

Extract data – Section ranges

Extract data – Phrase means

Extract data – Phrase

Data extraction - Phrasing

Loudness -> more consistent

LMPD Method Local maximum on loudness per

phrase Phrase strength (clarity)

Difference between max and adjacent mins Phrase volatility

Standard deviation of strength over performance

Phrase typicality (uniqueness) Popularity of location of max

LMPD results 1/2

LMPD results 2/2

LMPD Conclusions Finite number of local maxima counts Phrase strength and volatility relates

to listening perception Typicality (uniqueness) vs greatness

of performance

General conclusions Significant differences between

tempo and dynamics consistency with phrasing strategy

Different constraints of tempo and dynamics, different perceptions

Dynamics more consistent in this analysis, opposite on other studies

Cultural constructs