https://clara.imslp.org/

The ultimate goal of the IMSLP is to gather all public domain music scores, in addition to the music scores of all contemporary composers (or their estates) who wish to release them to the public free of charge

IMSLP currently has 231,406 works, 755,950 scores, 83,070 recordings, 27,907 composers, and 2,027 performers.

Fall 2024, so you don’t have to read the article