Reads a MusicXML score and writes it as a song beside it, one part per part of the score, that plays the whole score once.
mix mx.import score.mxl --tempo 100 --part "Soprano=oboe" --part "Bass=cello"--part names the synth a part plays on, and a part without one plays on tri.
--tempo sets the tempo, which otherwise comes from the score's first metronome mark.
--out names another path for the song, and --force writes over a song that exists.