Fig. 5. Cutoff time in PL+P pieces as a function of piece length.

The red points show the cutoff times of classical pieces (both single movements and full compositions) presenting a PL+P shape in their PSD estimation as a function of their total length. The black points present the same relationship, for all jazz solos of the Weimar Jazz Database (for details, see next section). For jazz improvisations, we observe a higher density of points around 128 and 256 quarter notes (32 and 64 bars in 4/4 time signature), which are very common durations of solos. For classical compositions, one can see an increasing trend between the lengths of PL+P pieces and the cutoff periods. This trend is somewhat less pronounced for jazz solos.