While no other high-profile pop-music act has released its catalogue this way, plenty of Internet companies allow you to build custom CDs from databases of thousands of songs. A couple of these companies, including CDNOW, are concentrating on familiar holiday tunes but will no doubt add a greater variety later. Others, like Cductive.com, specialize in particular genres, such as techno and dance music. Few if any of these companies, though, have the selection to draw in large audiences. Musicmaker.com has categories for Bob Dylan, Jagger/Richards, and Lennon/McCartney, but it doesn't seem to feature any songs actually performed by the artists, just versions by other people. Use of the Beastie Boys catalogue is limited as well -- you can build a two-disc set entirely out of their songs, but you can't add Beastie Boys songs to a disc with other artists. Still, what's interesting about these services isn't really the product they currently offer; it's that their success, or failure, may suggest how soon we'll see an all-digital, all-downloadable music business.

There are several hurdles on the road to a downloadable music economy: first, consumers' comfort with building collections for themselves, outside of the traditional album format, and second, their comfort with purchasing music solely online. The third (and perhaps biggest) hurdle is consumers' willingness to give up a physical product and accept a digital one, like an MP3 file, as a music purchase.

The success of Amazon.com and other e-commerce ventures has already shown that the public is perfectly willing to shop online. When it comes to selling music, online stores may even have some advantages over their brick-and-mortar competition -- at retail outlets it's difficult, often impossible, to hear a record before you purchase it, while most online companies (including Amazon, barnesandnoble.com, and CDNOW) offer short, downloadable samples of several songs per album. Musicmaker.com's Beastie Boys collection includes a thirty or forty-five second sample of every song offered.

Still unproven is the public's willingness to move away from the album format. Since the late sixties, the prevailing format for new music has been the LP (for "long player") -- a group of songs by a single artist intended for release as a discrete set. Even now, while singles are what's played on the radio and MTV, those singles are songs carefully selected to drive album sales, especially in the U.S. (CD singles are less popular here than in, say, the U.K., where an artist will often release a two-part single -- two discs meant to eventually be held in the same package but sold separately.) A customized CD service, though, will allow customers to select and compile only those singles (and "album tracks," or songs not released as singles to radio and MTV) that they want, essentially negating the artist's intent in collecting and sequencing a group of songs.

This process, though, still retains an analog, or rather a solid, portion: ultimately the music you select is burned onto an actual disc, a cover is printed, and the whole package is mailed to you. Until MP3 players (essentially small hard drives onto which you load sound files from your computer) become as prevalent as the Walkman (or the car stereo), this tangible aspect of online music buying will remain. Except for early adopters -- such as college students with fast Net connections and money to spend on the first Walkman-type MP3 devices -- most music buyers, like most book readers, still want something to hold on to, something to prove that they own the songs they've chosen. Most of us are perfectly happy to listen to the radio without taping it for posterity, just as we're perfectly happy to read and then recycle a magazine; but records, like books, remain non-disposable -- they are things to be put on shelves in living rooms, totems that help us define our characters. Only when we're willing to give up the tangible -- perhaps when our data can follow us around as easily and as securely as a book or CD can be stuffed in a briefcase -- will downloadable music eclipse the compact disc.

--Ben Auburn