@libraz/libcantus - v1.1.0
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    Type Alias TrackRole

    TrackRole: "melody" | "harmony" | "bass" | "drums" | "other"

    The musical role a track plays in the arrangement.

    Only drums changes the analysis: its pitches select instruments rather than naming harmony, so such a track is excluded from chord and key inference and from every voice-leading comparison, and is reported back with no annotations. harmony is meaningful through ArrangementOptions.harmonyTracks, which names the tracks the chords are inferred from. The rest are labels carried through to TrackAnalysis.role for the caller's own use; nothing is inferred, so a track left unlabelled reports 'other' rather than a guess.