Comment by charlesism

    the music barely at all.

I suspect the reason that excerpt sounds so bad is because the music has several instruments playing at once. One doesn't generally design a vocoder to deal with more than one voice. As that except plays, you can hear that the most prominent instruments (eg: the bass at several moments) sound pleasing, albeit speech-like.

It would probably different from the original music, but pleasant, if one processed each track separately.