- A type of Stream. See music21.stream.
- A notated music event. See User’s Guide, Chapter 2: Notes or music21.note.
- A representation of fundamental frequency. See User’s Guide, Chapter 3: Pitches, Durations, and Notes again or music21.pitch.
- An object that connects multiple objects in various Streams. Spanners include
things like Slurs and Glissandos and also StaffGroups (which links Part objects
that should have brackets around them).
- A music21 object for containing objects. See Overview: Streams, Scores, Parts, and Measures or music21.stream.
- The 14th century in the Italian, which is odd because it means 300, but it’s short for
the 1300s. The creator of music21 works on Italian trecento music, so you’ll see a lot
of references to it here.