Function reduce_chords 

pub fn reduce_chords(
    score: &Stream,
    options: &ReductionOptions,
) -> Result<Stream>

A score reduced to its chords: music21’s ChordReducer.run, which hands back a score of one part, the first part’s measures holding the chords.

Errors

A stream that is not a score or has no part, a meter that cannot weigh a slice, or a length no duration can have.