Red Sox fan? It's time for a postgame playlist

These, then, are some of the songs that a red-blooded BoSox fan might want to listen to today: "Heroes" by David Bowie. "Meet My Team" by Robert Pollard. "Who's the Greatest Red Sox Fan?" by Phil Coley.

And, of course, Queen's "We Are the Champions."

"This grew out of thinking, 'What are the things that exemplify hope, and heartbreak and love, and then sheer elation?'" said Cappello, who later sent her RealNetworks Rhapsody playlist to other fans. "It was a way of expressing the feeling. You can't really get up on your desk and dance and sing, so you might as well put on your headphones and rock out to your own little Red Sox world."

Cappello is hardly alone. Digital-music playlists have replaced mixed-album cassette tapes as instant snapshots of the music zeitgeist, with the advantage that they can be compiled on the fly and sent to dozens of people online at once. Events like the Red Sox win or the presidential elections now routinely inspire fans to create song lists that serve as their interpretation--or simply celebration--of the news.

Indeed, most of the online digital music services have latched on to the idea of the free-form playlist as one of their most potentially powerful marketing tools, although they're just beginning to experiment with how the idea can be used.

Rhapsody has a feature to let subscribers share playlists with one another, and even to post them on blogs to be downloaded by others. Because Rhapsody is a subscription service, any subscriber who downloads someone else's playlist has immediate access to all the songs listed. Subscribers to Yahoo-owned Musicmatch have a similar capability.

A small but growing subculture of playlist blogging has developed around the feature, with people sharing themed lists ranging from "Flu Vaccine Blues" to "Rock and Roll Jesus." A number of political-themed lists are circulating as well.

Robert Burke, a South Carolina software tester, has run an extensive playlist blog for the last five months featuring lists from both the Rhapsody and Musicmatch services. He said he sees the playlists as a way to notice connections between songs that might otherwise be missed.

"You can really learn something--like in a list of songs produced by Brian Eno, you can hear how that producer works," Burke said. "You can really expand your knowledge that way."

Digital download stores like Apple Computer's iTunes are focusing just as hard on playlists as a promotional tool, though each song must be separately purchased. Apple touts playlists made by celebrities and offers a whole "iMix" section filled with playlists made by its customers--more than 122,000 at last count.

iTunes also has an "October Baseball" playlist posted that's diplomatically nonpartisan. It includes songs such as "Take Me Out to the Ball Game," "Who's on Third" by 3rd Bass, and the "Baseball" routine by comedian Bill Cosby.

Baseball-loving musicians in Houston and St. Louis may want to start writing quickly, because both teams are tragically underrepresented in the canons of popular music.

And sadly for Red Sox fans, none of the surely admirable songs created for a Boston radio station's "Yankees Suck" contest seem to be available through the major music services. But there's always Google.