Many readers may have been aware of the thousands of free e-books available on Project Gutenberg, but did you know they also have music? The Gutenberg Sheet Music Project, thanks to the work of many volunteer hours, has digitized public domain sheet music, using a variety of techniques (MIDI, PDF, MOBI, plain text, etc.), to enable study and performance. For the most part, the musical pieces created have been chamber music, with composers such as Brahms and Beethoven. A great incentive to getting together your own community music group!