Here is my third interview. I spoke to Paul Lamere (pictured left) just an hour or two after my chat to Zac Johnson. Some of their points overlap with each other: for example, Paul's Green Day/Weezer/Radiohead argument about collaborative filtering is pretty similar to Zac's, which he illustrated with the Beatles/Bob Marley/James Brown. However, there are also minor differences and nuances of emphasis, reflecting, perhaps, the perspectives of their employers.
Paul Lamere works for Sun Labs in Boston, where he's the Principal Investigator for a project called Search Inside the Music. Unusually among industrial research labs, Sun's are funded from the corporate treasury, rather than product groups, which gives them greater scope for blue sky thinking, while still focusing on the needs of Sun's customers, who include a variety of high-profile music service providers.
Paul is interested in the whole music discovery process. Citing the long tail effect, he sees the challenge as providing the link between a million songs in the backroom and the mobile device in your hand. The ideal would be to have an option on that device that just says "play me music I like".