The company I work for once used one of the larger stock image libraries to do the rights search and negotiate for us. As others have pointed out, the process isn’t cheap. There was an up-front charge, and you pay it regardless of whether or not you can secure the rights.
All involved parties (record label, recording group, composers and publisher) must be contacted and come to an agreement to license the material, and many times those parties have to be negotiated with individually. Some or all of the parties involved might also have a most-favored-nation clause, which can drive up the cost pretty quickly.
And did I mention, the band doesn’t take American Express? It wasn’t quite as bad as a request for cash, in small, unmarked bills, but it was close with a ridiculously short turnaround.
Be prepared for a five-to-six figure quote for the music, depending on usage.
In the end, a great learning experience.
As this was several years ago, the situation might have changed. And if the performer is media savvy (think Moby), you might luck out.
Good luck.