If you’re a dedicated cubicle monkey, then no doubt your best friend is a pair of great headphones and either Pandora or Slacker Radio (or Grooveshark, for that matter). But have you ever stopped and wondered how the music sites keep the eclectic playlists flowing?
Pandora has a catalog of more than 750,000 songs – far fewer than you might see with streaming music services like MOG, Napster or Rdio. Each song is reviewed by a member of Pandora’s review team and characterized according to nearly 400 musical attributes before being added to the Music Genome Project. The project is “the underlying backbone” behind Pandora, Westergren told us.But how do we get from this to the songs being streamed over your headphones? According to Westergren, the Music Genome Project provides a sort of “musical DNA,” and from there the site is constantly trying to shape what it plays next according to your tastes. On Pandora, users can provide feedback in the form of thumbs-up and thumbs-down to influence the songs the site plays.
“Over time, we try to figure out the patterns in your thumbing,” said Westergren. “It’s really trying to replicate the knowledgeable record store guy – the human who knows what you like and don’t like.”
Giving a thumbs-down to a Joni Mitchell tune, then, won’t limit your playlist to male vocalists, but if you continue over time to thumbs-down female vocalists, the system is designed to pick up on this pattern and cater your channel accordingly.