When Is a Piece of Music Finished?

Wow - thinking about Ives and his accusers, what a beautiful statement from composer and loyal respondent Art Jarvinen:

About that conception that Ives went back and "updated" his scores, to make it appear that he was ahead of his time or whatever: When I was reading the Swafford bio on Ives it struck me that he was probably just a lot like Frank Zappa.

When I worked for FZ as a copyist one of the things we were working on was the score to 200 Motels, which had long before been "finished", recorded and released. He wanted it all cleaned up and copied beautifully according to the state of the art hand copying methods of the time. It was immediately apparent that the score I was looking at didn't exactly match the record. We were working from a revision.

I also did reductions for two pianos of most of his orchestral works and saw the same thing. Pedro's Dowrey, recorded on Orchestral Favorites, has a lot of changes, and is different still by the time he gets it done by the London Symphony. The entire ending is different in fact. Frank paid me put a band together to play Pedro in my two piano version plus percussion, bass, and trombone, planning to record it. But then the LSO deal fell into place and my version became moot. But he used the band as a testing ground, and had Kent Nagano conduct us through it and replaced our percussionists with his guys. All through the rehearsal he was changing things, and having Chad Wackerman play the drum part with different feels - "Now make it reggae."

The piece he did for the E.A.R. Unit - While You Were Art - came out on Jazz From Hell completely reworked as WYWA II.

What I observed by seeing his music so close up and watching him work was that nothing he did was ever really finished. It was all work in progress, and he changed it every time he went back to it. Records exist, and bands would play a version of a piece for a while, but that's what they were - the versions of that moment.

Ives published his works, but that doesn't mean that in his own mind those were THE definitive versions. I think that if he had an inspiration or learned a new trick or just wanted to see what the effect would be if he did it "this way", he took the liberty to do so. It was his music, to do with as he pleased. No one says Frank Zappa was revising his works because he didn't get them quite right the first time, and I see no reason to think Ives was up to some trickery.

Who says a work of art is finished, and at what point? Exhibition, recording, publication?

I think some artists just work, and the "work" is over when they die. What we may be left with are several versions of the same piece, all equally valid.

Is Frank Zappa hereby discredited? If not, why the musicological glee among those who attempt to discredit Ives?