OpenScore

[dave2010]

I just encountered this web initiative - OpenScore - https://openscore.cc/#home

For an example, try this Beethoven - https://musescore.com/openscore/scores/5733014 - in MuseScore. Wild sounds indeed - but you could export as Midi, and import into other systems, such as Sibelius, or various DAWs to get better instrumentation.

Give it a whirl. Note - you can play this as well as look at the score - it's very weird!

See also this list of MusicXML sites - the music of Ponchielli and Beethoven String Quartets (Project Gutenberg) could be fun.
https://www.musicxml.com/music-in-musicxml/

https://www.shsu.edu/academics/music/ponchielli/

https://www.gutenberg.org/wiki/Guten..._Music_Project

Also, since it's nearly Christmas, here are some carols - http://www.hymnsandcarolsofchristmas...L/musicxml.htm - thought these don't seem to work in my system.