Individual Decisions and Perceived Form in Collective Free Improvisation

Abstract

This paper proposes a first attempt to study quantitatively Collective Free Improvisation (CFI). We report an experiment designed to study the relationship between the improvisers’ individual high-level decisions and the improvisation’s form perceived by external auditors. We recorded 16 trios in which the improvisers used a MIDI-pedal to indicate in real-time a significant change in their own musical production. Expert listeners were later asked to segment each improvisation so that we obtained their perception of the structure. By analysing the correlations between musicians’ individual decisions and listeners’ segmentation points, we discuss how the improvisation’s form emerges from the improvisers’ individual behaviours. While the overall structure depends on individual contributions and decisions which can be well-identified, it is never fully determined by them.

Keywords:

• improvisation
• interactions
• emergence
• segmentation
• empirical musicology

Notes

1 See for example Schönberg, Fundamentals of Musical Composition: ‘form means that a piece is organized: i.e. that it consists of elements functioning like those of a living organism’ (quoted in Grove Musical Online, ‘Form’).

2 See Nunn (1998): ‘Just as the smaller units of music are gestural by nature, so are the larger units of form. As such, a “section” can be thought of as a “formal gesture”, which articulates a particular musical character. Together, these “formal gestures” tend to create a segmental form - numerous sections with specific musical character adjacent to one another via transitions’ (Nunn , 1998, p. 29). See also Borgo (2005): ‘Many of the most effective collective improvisations, it seems, involve decisive musical “phase spaces” (in the language on nonlinear dynamics) and transition between phases, all negotiated by the group with an awareness of what has occurred and a conception of what may follow’ (Borgo , 2005, p. 61).

3 This distinction is clearly made by composer and improviser Vinko Globokar in the score of Individuum Collectivum (1979): ‘Composed music usually possesses a form based on foreshadowings of what will happen latter and on remembrances of what has already happen. Improvisation, conversely, is linear: it follows a causalistic logic’ (section 32c, translated from French).

4 We don’t have enough data to discriminate between Gaussian, Poisson, Gamma or exponential distributions.

5 This can probably be explained by the improvisers’ limited cognitive resources, making difficult to generate their own signal while at the same time finely monitoring each of their co-improviser’s signals (Canonne & Garnier , 2011). This is also coherent with the findings of a recent study on the members of a string quartet which shows that even in the somehow rigid and hierarchical environment of the performance of one of Haydn’s string quartets, there is room for differentiated and moving patterns of dependencies in the group (Timmers, Endo, Bradbury, & Wing , 2014). The dynamical sub-grouping of musicians is thus probably a general feature of all interactively produced music.

6 The purely random model of segmentation described in Appendix C gives %, %, % and %.

7 This is consistent with the results of a previous study (Canonne & Garnier , 2012), in which improvisers were asked themselves to segment their own collective improvisation immediately after playing: the same types of ‘cues’ were found to be used by the musicians as a basis for their segmentation.

8 In Sound Example 7, the three musicians press their pedals in the time interval [14”–18”].

9 This cyclic movement has been clearly described by the composer and improviser Frederic Rzewski: ‘All improvisation has its own natural form; Zero: beginning with nothing, fumbling; Accumulation: slow rising, long duration; Peak: stable plateau, relatively short; Exhaustion: rapid falling back to zero. A sort of modified square wave: like breathing, a natural rhythm’ (Rzewski , 2007, p. 282).

10 As Borgo puts it: ‘The (perhaps unique) challenge of free improvised music, then, is to provide this heightened sense of expectation and surprise to both audience members and to other performers collectively, in a more or less bottom-up fashion’ (Borgo , 2005, p. 139).

Additional information

Funding

The authors wish to thank the Institut Rhône-Alpin des Systèmes Complexes (IXXI) for financial support.