A Stream of Bills: Startups Making Money For Music’s Middle Class

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Click for full photo gallery: 12 Music Jobs That Can Pay Six Figures

Elmo Lovano has worn many hats in a career that began in his teenage years—as a drummer, musical director, producer and promoter—working with artists from Skrillex to Miley Cyrus along the way. Now he’s adding another: startup entrepreneur.

This week Lovano’s service, Jammcard, made its debut in the iTunes store; it will allow musicians to find others with whom to perform paid gigs and session work. For Lovano, ins...