If Internet dating sites can match people by trying to compute the elements of attraction, why can't songs be matched with people in the same way?

That's the idea behind Pandora (www.pandora.com), a new Web service that tries to match music you like with other tunes that share the same qualities. Pandora Media, the company behind the service, has been selling music-discovery software for years to big retailers such as Best Buy. Its Pandora service is the company's first offering based on an unusual musical study it dubbed the Music Genome Project.

Over the past five years, a team of analysts studied songs played by more than 10,000 artists and attempted to classify their traits -- not just which instruments are played and what the rhythm is like, but the melodies, lyrics and hundreds of other variables. Much as genes shape humans, the analysts theorized that certain describable qualities shape music and therefore should govern our musical tastes.

As implemented in Pandora, this technology works like a personalized Internet radio station. The site creates a playlist for you after analyzing a particular artist or song that you say you like, then streams the music that it thinks matches your tastes. Pandora lets people listen to these "stations" for free for 10 hours; afterwards, a subscription costs $36 a year.

You don't get to own or download the tunes Pandora picks for you, although the site will refer you to Amazon.com or the Apple iTunes Music Store if you decide to purchase them. You can't control the order in which they are played or replay one you like. Those are the terms of the licenses Pandora negotiated to bring this music-discovery service to market at a relatively low cost. Its song library excludes classical but includes all sorts of rock, jazz, hip-hop, blues, R&B, country and electronic music.

That sounds intriguing, but can anyone classify the distinctive sound of human voices, especially those of many famous singers?

In a test, I had Pandora create an "Elton John" station based on other music that supposedly shares the qualities of his work. First up was a bizarre number called "Thee Andes Tune" by Footch Kapoot, followed by "Live for Today" by Toto -- which didn't bring to mind Elton John, either. Pandora did better with its Sarah McLachlan sound-alike station, streaming two tunes that sounded eerily similar to hers, one from Alice Peacock and another by Chantal Kreviazuk.

One pleasant feature of Pandora is that it will tell you why it's playing a particular song, citing the musical attributes the tune supposedly shares with the artist or song you picked. For Elton John, the attributes cited were "mild rhythmic syncopation, a subtle use of vocal harmony, major key tonality, acoustic rhythm piano and mixed acoustic and electric instrumentation."

Sounds good, but who would have thought such wonkish qualities defined one of pop's greatest singers?

PBS's TV-Free Debut

PBS is moving deeply into Web video, and not just with online copies of such well-known TV shows as "The NewsHour with Jim Lehrer." Last week, the Public Broadcasting Service introduced an Internet-only video show called "NerdTV." It consists of weekly one-hour interviews with computing pioneers and experts, starting with Andy Hertzfeld, the original programmer for Apple Computer's Macintosh. The site says these downloads can be viewed in a variety of video-player programs, but recommends Apple's QuickTime.


E-mail Leslie Walker at walkerl@washpost.com.