YSK: IMSLP (International Music Score Library Project/Petrucci Music Library) is an online library that contains thousands of free public domain music scores/sheet music and recordings for download
from /r/YouShouldKnow
YSK: IMSLP (International Music Score Library Project/Petrucci Music Library)是一个包含数千首免费公共领域乐谱/乐谱和录音供下载的在线图书馆。