music21: picking out melody track
<p>I'm processing a bulk of midi files that are made for existing pop songs using music21.</p>

<p>While channel 10 is reserved for percussions, melodic tracks are all over different channels, so I was wondering if there is an efficient way to pick out the main melody (vocal) track.</p>

<p>I'm guessing one way to do it is to pick a track that consists of single notes rather than overlapping harmonics (chords), and the one that plays throughout the song, but is there any other efficient way?</p>