Sean Parker is a human accelerant, an idea catalyst who, when combined with the right people, has fueled some of the most disruptive companies of the last two decades. At just 19 he blew up the record industry as the cofounder of the music-sharing site Napster. Two years later his address book service, Plaxo, demonstrated the potency of digital propagation, something he took a step further as the 24-year-old president of Facebook, helping the social network become the most important Internet company since, well, maybe ever.

Parker’s path to Silicon Valley began the day his father, Bruce, formerly the chief scientist at the National Oceanic and Atmospheric Administration, taught him how to program on an Atari 800. He was in second grade. By high school Parker was hacking into companies and universities (alias: dob, which he chose for its aesthetic symmetry).

Napster was the transition between CDs and MP3s after the Internet made it possible to strip content from its container. Facebook was a vehicle to create a reliable identity in an anonymous online world. Spotify is an attempt to fix the very music industry that Napster helped break a decade before.

He never did make it to college, but Napster provided an education all its own. “I kind of refer to it as Napster University—it was a crash course in ­intellectual property law, corporate ­finance, entrepreneurship and law school,” says Parker.

“He thinks about where he perceives the world to be going,” explains Spotify founder Daniel Ek. “If he doesn’t think there is a company that will win, then he builds it himself.”

He’s hunting new startups as general partner at venture firm Founders Fund and reuniting with Napster’s Shawn Fanning to create Airtime, a live video site.