Age: 44
Occupation: Founder, Pandora
Previous TIME 100 Appearances: 0
You know that friend who always is able to recommend a record that you'll love? Westergren turned that friend into a computer. He married his Music Genome Project, a system that categorizes traits in songs and uses the data to recommend similar selections, with the Internet radio player Pandora. The result? A service that was almost too popular for its own good. Record companies lobbied hard to earn some revenue from Pandora's millions of streaming songs, but the company avoided closure in 2009 by negotiating reduced royalty rates and offering paid-subscription plans for the first time.