Musical Creativity and Depth of Implicit Knowledge: Spectral and Temporal Individualities in Improvisation

Abstract

It has been suggested that musical creativity is mainly formed by implicit knowledge. However, the types of spectro-temporal features and depth of the implicit knowledge forming individualities of improvisation are unknown. This study, using various-order Markov models on implicit statistical learning, investigated spectro-temporal statistics among musicians. The results suggested that lower-order models on implicit knowledge represented general characteristics shared among musicians, whereas higher-order models detected specific characteristics unique to each musician. Second, individuality may essentially be formed by pitch but not rhythm, whereas the rhythms may allow the individuality of pitches to strengthen. Third, time-course variation of musical creativity formed by implicit knowledge and uncertainty (i.e., entropy) may occur in a musician's lifetime. Individuality of improvisational creativity may be formed by deeper but not superficial implicit knowledge of pitches, and that the rhythms may allow the individuality of pitches to strengthen. Individualities of the creativity may shift over a musician's lifetime via experience and training.

Keywords: Implicit learning; Markov model; characteristics; entropy; hierarchy; n-gram; statistical learning; uncertainty.

Figure 1

Representative phrases of transition patterns in pitch sequence without rhythms (A), rhythm sequences without pitches (B), pitch sequence with rhythms (C), and rhythm sequences with pitches (D). The musical information was extracted by listening music information recording media and originally written for the present study.

Figure 2

Principal component analysis scatter plots in pitch sequence without rhythms (A), rhythm sequences without pitches (B), pitch sequence with rhythms (C), and rhythm sequence with pitches (D). The horizontal and vertical axes represent principal component 1 and 2, respectively. The dots represent each piece of music.

Figure 3

The difference in TPs among W.J. Evans (red), H.J. Hancock (blue), and M. Tyner (green) in pitch sequence without rhythms.

Figure 4

The difference in TPs among W.J. Evans (red), H.J. Hancock (blue), and M. Tyner (green) in rhythm sequences without pitches.

Figure 5

The difference in TPs among W.J. Evans (red), H.J. Hancock (blue), and M. Tyner (green) in pitch sequence with rhythms.

Figure 6

The difference in TPs among W.J. Evans (red), H.J. Hancock (blue), and M. Tyner (green) in rhythm sequence with pitches.