Comment by tdumitrescu

Take from a musicologist and semi-professional performer: IMSLP is great for finding quick scores of random stuff, but the editions are often pretty shoddy, like either super outdated with weird editorial decisions that no one's agreed with for the last 50 years, or someone's totally amateur transcription full of errors and equally weird decisions. Treat it like you might treat Wikipedia as a research source (ok as an initial point of entry, but soon you want to dig into the real sources).