"There is a built-in business model here: smart advertising. Artists can pay to have their songs cued up to FOO listeners in exchange for BAZ dollars."

Ok, but how do you intend to actually get this advertising money? It's not as simple "if you build it, they will come". You need to be able to sell the site to advertisers. I didn't see anything in your "About me" background that makes you qualified for the "make money" part of this venture. Or you just planning to sell it to someone else to make that happen?