I'm not a lawyer, so someone more knowledgeable can chime in, but this is what I perceive to be the case.

Although in light of recent litigation decisions, I'm not sure, but from what I understand you can can copyright your melody and lyrics. You can't copyright the arrangement and the chord progression. You can copyright your recording of it as a whole piece, though, so I couldn't just take it and sell it for my benefit.

I could be wrong, but I suspect that if you just generate an arrangement with BIAB and I generate the same arrangement with BIAB (it can happen, or at least be close enough that discerning ears couldn't tell the difference) that neither of us would not be able to claim copyright on that arrangement (mainly because there is no melody) but that, because PGMusic has authorized you to use their intellectual property in your songs, then that part of the song is probably de facto in the public domain and can't subsequently be copyrighted by you. That doesn't mean that you can take RealTracks, for example, wholesale and sell them to other people as your own. But used in the creation of your song, you can copyright your song. You can copyright the stuff you came up with, though.

I'm sure it's more nuanced than that, but hopefully that made sense.

John

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