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Duration of playing bursts and redundancy of melodic jazz improvisation in John Coltrane’s “Giant Steps”

Studying musical improvisation is methodologically difficult because improvisations are hardly reproducible, and no established theory exists regarding their formation. In particular it is unclear when and if jazz musicians invent new (innovative) melodic patterns or rely on previously overlearned (redundant) phrases. Other similar goal-directed activities with high complexity are production tasks such as driving a car (Tanida & Pöppel, 2006) or producing spoken language (Fenk-Oczlon & Fenk, 2009). Trade-offs between deliberate cognitive processes and automatized execution can be expected under extreme time pressure in high speed improvisation, and pauses in the musical flow could be used by musicians to engage in generative cognitive activity. Using transcriptions of John Coltrane’s improvisation of “Giant Steps” we analyzed redundancy and innovation in melodic improvisation. Half-bar units were coded for types of melodic variants. We found motor-output units (playing bursts) of around 3 seconds’ duration with a slightly higher probability of innovative patterns appearing after longer (0.5 s) pauses. Also, a systematic curvilinear trajectory of innovation was found across the piece with a peak after three-fourths of the chorus. The discussion establishes a parallel between improvisation and conversational language production with regard to the length of utterances which seem to take into account the listener’s psychological present. The possibilities of expert improvisers to engage in deliberate problem-solving during performance are also addressed.