>>714870203
Musopen is also a pretty neat website that records performances (or at least, used to) of classical music, and have them released to the public domain. In fact, they are the source of some recordings in the Internet Archive.
Classical music in general is a bitch concerning copyright because inevitably a performance you can use/you're literally doing will sound close enough to a copyrighted performance you cannot use, and your video/stream will be taken down.
https://www.washingtonpost.com/entertainment/music/copyright-bots-and-classical-musicians-are-fighting-online-the-bots-are-winning/2020/05/20/a11e349c-98ae-11ea-89fd-28fb313d1886_story.html