SOLVED. Time travelling music student kidnaps Schubert [s]

[Charlie]

I read this book in the early 1990's. It was a sort of science fiction comedy. I cannot remember the title or the author, but I remember the book quite well and I would really like to read it again.

It was about a music student at UC Berkeley who was a bit of a charlatan. He wrote a dreadful cacophony as his final school assignment and tried to pass it off as avant garde with limited success.

To make ends meet he worked as a janitor on campus. A physics professor invented a time machine and used it to travel to California's past and mine for gold. The physics professor got killed by indians and the music student took the machine.

He used it to kidnap Franz Schubert, take him into the far future, cure his syphilis, and use him to compose music that the student published under his own name.

There were complications. He was discovered by a man and a woman. He sent the man back to the 1920's but gave him decades of newspapers on microfilm that the man used to get rich by trading stock - until he caused the crash in 1929 by selling it all. The woman was sent into the future and stranded there with Franz Schubert.

Please. This is driving me crazy and I've done every search I can think of. Am I the only person who ever read this sci-fi pulp?

[K.]

Could this be Mixed Doubles by Daniel da Cruz? The Goodreads page for this book doesn't have the summary, but online searches for it come up with this:

"Justin Pope, a music major, stumbles upon a time machine that he uses to kidnap Franz Schubert from his deathbed; Pope cures Franz and uses him as a source of compositions to create a magnificent career of his own (with the help of Angelica), until Franz turns the tables (with the help of Philipa)."

[Charlie]

Yes!! Yes! Thank you, thank you, thank you!

[Cheryl]

Mixed Doubles, for the link - I'm off to add a description, but for fear of breaking copyright I'll have to be brief.