IMSLP: Petrucci Music Library
Ad-free access to IMSLP (International Music Score Library Project). Run by Project Petrucci LLC, it is the largest collection of freely available scores/recordings on the Internet, sharing the world’s public domain music scores in any genre (classical, folk, and so on) and scores of any contemporary composers who wish to release them to the public free of charge. Visitors can browse the works of some 17,875 composers and almost 500,000 scores by time period, nationality, and instrumentation. Information on the composer, key signature, publication date, and style is posted on each page. A keyword search is also available. PDF versions of the scores can be downloaded and printed. Many works also have MIDI and/or MP3 recordings, which can be heard immediately or purchased online.