Listen
Listen.com's approach is entirely different from MuBu's. Listen.com relies on the expertise of "obsessive music junkies" to define the music in its database. Its editorial staff is 30 strong, and it prides itself on being the authority on all music across all genres. Tim Quirk, Director of Editorial at Listen.com, describes its filtering process as a return to the basics: "The most important thing is that we do it the old-fashioned way. All the connections and recommendations that we make about artists are made by human beings. And not just any human beings, but by obsessive music junkies. We have a huge editorial staff, and we hire only people who know music backward and forward."

Tim Quirk, Listen.com Director of Editorial

As new bands are presented to the Listen.com force, an editor will listen to the entire piece of music. Then, using the 500-genre style tree (the OED of music, as some insiders describe it, which features such subgenres as pop, classic rock, punk, Latin, gangster rap, etc.), the editorial staff defines the song as specifically as they can. Finally, they include three to five artists they deem to be similar to the one in question. This allows you to discover new bands that are based on the ones you currently like.

Listen.com Related Artists

Quirk stresses that Listen.com's system is less a collaborative filtering system and more a "know-it-all filtering" process. He further describes this concept, "Basically, it's so refined that you can pinpoint the exact music that you want to listen to. Every song in our database has been listened to by a human being. An editor assigns it to genres from the style tree and then assigns two to four similar artists. When you type in the name of a band, you'll see similar artists listed below the name. The first three to five related artists are names that the Listen.com staff has entered, and all the rest are bands that have had the artist that you typed in assigned to them. So the relatedness goes in both directions, so to speak."

Currently, Listen.com has more than 160,000 bands in its database of music, and the numbers are increasing at a rate of some 5,000 per month. I was most impressed with the fact that only 30 editors were handling this load, though Quirk assured me that Listen's sturdy staff was well equipped for the challenge. "It really is hard to keep up with the increasing numbers of artists. In the first year, we manually reviewed and wrote a blurb about every song and artist that passed across our desks. Now, we'll still listen to everything and assign genres and similar artists, but we'll probably place blurbs only on the stuff that we consider to be good."

The human approach of Listen.com should be reassuring for those who fear algorithms. At Listen.com, they're proud that every band has been scrutinized by a human being (and a music junkie at that.) Perhaps Quirk best related this human element when remembering how Listen.com termed its recommendations. "This is all done based on the knowledge of human beings. The editors fought hard to have the recommendations be called 'similar artists' as opposed to 'sounds like.' As we all know, a band's style can vary greatly from song to song, and we want the user to appreciate that."

The mysterious gigaspiral, revealed!