Extended Data Fig. 2: Examples of canary song phrase sequences, rare inter-phrase gaps, and aberrant syllables.

a, Additional spectrograms of phrase sequences (colours above the spectrograms indicate phrase identity) that lead to a repeating pair of phrases (pink and yellow). b, Examples of flexible phrase sequencing comprising pitch changes (from bird 3). c, Examples of phrase transitions with a pitch change from bird 2. d–f, Phrase sequences showing changes in spectral and temporal parameters. d, Bird 1 changes from up sweep (purple) to down sweep (dark red) through intermediate phrases of intermediate acoustic structure. e, Bird 1 shows a change in inter-syllable gaps. f, Bird 2 shows changes in pitch sweep rate. g, Top and bottom sonograms compare the same phrase transitions where the inter-phrase gap varies. h, i, The top sonogram includes a rare vocalization at the beginning of the second phrase (highlighted) that, in i, resembles the onset of an orange phrase type.