There has been considerable litigation around this subject, and IP questions can get really complex. E.g. if you're using a Real Book version of "Donna Lee" you got through a P2P site:
* You're using sheet music pirated from the authors of the real book…
* Who were transcribing the song without paying royalties to the rights holders (presumably Charlie Parker's estate)…
* Who were re-using the harmony of "Indiana" (and I'm not sure whether the legality of that has been conclusively established).
There has been considerable litigation around this subject, and IP questions can get really complex. E.g. if you're using a Real Book version of "Donna Lee" you got through a P2P site:
* You're using sheet music pirated from the authors of the real book… * Who were transcribing the song without paying royalties to the rights holders (presumably Charlie Parker's estate)… * Who were re-using the harmony of "Indiana" (and I'm not sure whether the legality of that has been conclusively established).