Projects the chromagram (normalized using the ‘Normal’ option) into a self-organizing map trained with the Krumhansl-Kessler profiles (modified for chromagrams) (Toiviainen and Krumhansl, 2003; Krumhansl, 1990).

The result is displayed as a pseudo-color map, where colors correspond to Pearson correlation values. In case of frame decomposition, the projection maps are shown one after the other in an animated figure.

mus.keysom accepts either:

• mus.Chromagram objects,
• sig.Spectrum objects,
• sig.signal objects, where the audio waveform can be segmented (using sig.segment), decomposed into channels (using sig.filterbank), and/or decomposed into frames (using sig.frame),
• file name or the ‘Folder’ keyword.

mus.keysom(..., ‘Frame’, ...) performs first a frame decomposition, with by default a frame length of 1 s and a hop factor of 50% (0.5 s). For the specification of other frame configuration using additional parameters, cf. sig.frame