J. Sider, 29, Founder, Bandpage

J. Sider. Top 30 Under 30.

BandPage, an online platform for musicians to build a presence and post content for fans. Today, the San Francisco-based company has more than 500,000 musicians as users–including big names such as Rihanna, 50 Cent, and Arcade Fire. The company uses a “freemium” model for musicians, who can purchase extra promotional tools, and also allows bands to sell unique experiences to fans.