Function to_tsv_with_extra 

pub fn to_tsv_with_extra(
    stream: &Stream,
    version: Version,
    extra: &[Vec<(String, String)>],
) -> Result<String>

A score written as a table, with the cells music21 keeps on each numeral’s editorial given back: one list per chord the walk meets, in that order, which for a score from_tsv read is the order of the table’s own rows.

music21’s reader writes every column it does not read onto the numeral it made, and its writer reads those cells back for the columns it cannot work out itself – which is how a table’s mc, staff, chord_tones and the rest survive a round trip. A chord here carries nothing of the kind, so they are the caller’s to keep: TabChord::extra is what tsv_to_chords reads them into.

Errors

As to_tsv.