How to share music legally?

WSJ.com's Vauhini Vara article Music Sharing Goes Legal On Web Radio starts with:

Srivats Sampath saw a puzzle: He wanted to find a way to share music online without breaking the law.

A better question might be how to share music with raising the ire of the RIAA?

But instead of downloading songs to their PC desktops, Mercora users can create playlists of their favorite music and, with a few clicks of the mouse, "broadcast" them over the Internet to fellow users of the service

But doesn't that require a broadcast license or paying fees to some organization or group?

Mercora pays annual fees and royalties to nonprofit groups such as SoundExchange Inc. and the American Society of Composers, Authors and Publishers, or Ascap, which pass royalties along to copyright holders based on the service's estimated range of listeners.

And along with those fees will come user fees and advertising.

Mercora, meanwhile, is experimenting with running contextual Google ads in its application, and an Amazon program that gives it a cut of the profit each time a user clicks on a link in the Mercora program and purchases music from Amazon ... Mercora says it will soon start charging for premium services but isn't yet providing details.

Sounds like a business model.

Hopefully, one day soon, the Supreme Court will teach us how to share music online without breaking the law (and without paying user fees or being subject to a barrage of ads).