“Customizable Internet radio such as Yahoo’s Launchcast.com has been around for years, but Pandora is a twist on the concept: Instead of relying solely on computer software to spit out playlists, Pandora draws on its Music Genome Project, a 6-year-old effort by a group of musicians to identify the hundreds of traits and qualities that form the building blocks of music — and then to map out each individual song within this framework, or genome. Genre disappears, and every song is at once relatable, however closely or distantly, to every other.”