Here's a few more to add to your initial "master" list above.

General artist services: (in alphabetical order) (Self promotion service for music artists, bands and songwriters) (Musician's hosting & DIY ecommerce sales solutions) (Spreading the Gospel through music by networking with Christian songwriters worldwide) (The foremost mechanical licensing, collection, and distribution agency for music publishers in the U.S. - HFA Songfile is the online song search and mechanical licensing tool for those who want to make 2,500 or fewer copies of a recording as a CD, cassette, LP, or digital download.) (A national talent scouting & referral service used by the top 100 record labels and a quarter million music industry professionals to find up-and-coming independent artists ready to take the next step.) (Musician's hosting and DIY ecommerce music sales service) (The industry-leading digital distribution company for the global independent music community.) (affordable "Do It Yourself" online CD and DVD production service) (Founded in 1895, the Music Publishers Association is the oldest music trade organization in the United States, fostering communication among publishers, dealers, music educators and all ultimate users of music.) (Connecting musicians and singers to paying jobs since 1969) (Music industry listings service) (Self promotion service for artists & bands) (The "best and most comprehensive" data base of Songwriters and Songwriter Resources on the Internet today!) (online musicians-for-hire talent pool marketplace) (online service to turn any website into a music store where the artists collect 100% of their sales)

Music Licensing Services:
Note: Most of these are FREE, but you're music has to get accepted to participate with their program. (must be accepted, pays 50%) (must submitt music & be accepted, pays 50%) (must have min. of 100 tracks to be accepted) (this service is mostly for labels) (must submitt music and be accepted, pays 50%) (must be accepted, pays 50%) (specializes in music licensing for advertising uses; costs about $20/month for "starter" package) (anyone can join for free and pay only 9% on completed licensing sales)

There's nothing remarkable about it. All one has to do is hit the right keys at the right time and the instrument plays itself. -- Johann Sebastian Bach