A very large library of music for video and other projects. It appears that they are changing their model a bit but still offer free licenses for YouTube projects and some student projects. Other uses will have a fee associated. The quality of music is very high and I have used this site a good deal in the past for student work.
Underdeveloped website for public domain classical sheet music. I would love to see better sites with the inclusion of much more public domain music that is easy to explore and navigate. Would love any suggestions!