You betcha. A letter stating authorization to play would be just fine. If an unsigned musician would like us to play their music, we'd be happy to put it in the playlist.If a musician or group is signed with a record label, we're covered because we pay royalies in a lump sum that are divvied up to pay the respective copyright owners. It's part of the contract. If they're independent, then the way they handle their distribution and licensing is up to them, so if they want to be on the ART playlist, we're good. Either way, I think we're covered.
The way our licensing agreement is written, extra moneys are provided for record companies licensing and royalties in addition to those paid for streaming audio service. Anything that isn't owned by record companies is up to us. For example, if we setup a station that played nothing but indie music and/or recorded material that we own, the we would not have to pay the licensed royalties to ASCAP, BMI and SESAC (via Live365). We could sign a waiver and not pay the licensing fees, and instead just pay for the streaming audio server.
Since we plan to play mostly music, we pay the licensing fees. We also plan to run programs like recordings of seminars at LSAF and things like that. We'd love to play independent artists, and encourage everyone to send in material that they'd like to hear.