You're going to hear sooner or later, and feel rather old when you do: The Beatles' first single, "Love Me Do," is now in the public domain, at least in Europe.

How could that be? Though not the most durable Beatles song, it hardly seems to be from another time, though given the passage of 50 years, it most certainly is. Remember '60s hysteria? The kids who wrote "Beatles" on their contact lenses because they couldn't think about anything else? The girls who saved the Kleenex tissues into which they'd wept at the Shea Stadium concert?

Yet the music itself doesn't feel Paleolithic. Though the world has been anything but stationary, pop music isn't as disposable as it was once assumed to be - one reason why the laws are on the verge of changing. By November, the European Union will vote to extend the copyright on recordings from 50 to 70 years. It's a potentially important moment in the world of art and commerce.

The "Love Me Do" news sprang across my screen on Friday from an unlikely source - the website Pristine Classical (www.pristineclassical.com), which specializes in remastering old classical recordings and was protesting the impending change by offering a remastered "Love Me Do," one of only two Beatles recordings (the other is "P.S. I Love You") released in 1962 and thus in the public domain before the door slams shut again this year with the copyright extension.

For a business as small and niche-y as Pristine - old symphonic recordings by the likes of Wilhelm Furtwängler, Arturo Toscanini, and Eugene Ormandy - extended copyright may not be catastrophic news, but it ain't good. Often, such indie labels are the only way these recordings will reach the public.

"Love Me Do" comes with a very different set of concerns. British rock star Cliff Richard, now 72, has been agitating for years to extend the copyright expiration date. Who thought that would be necessary (or that any rock star would live so long)?

That evergreen quality of pop music is just what fuels the copyright changes. The compositions have extended protection, but they're no longer the central entity of the music business, a change from the early '60s, when a hit such as "I Left My Heart in San Francisco" could be identified with Tony Bennett but recorded by plenty of other singers. There was also a big subculture of knockoffs. When Harry Belafonte's "Banana Boat Song" started to turn into a hit, no-name performers hustled into recording studios to do their own versions.

That practice became impossible with the Beatles. By the time they got to such high-concept songs as "A Day in the Life" in 1967, the songs' most intriguing elements - like "A Day's" fantastical orchestral crescendo - couldn't even be translated into sheet music, much less imitated by anybody. You might stumble across a Bing Crosby version of "Hey Jude" that seemed pathetic if only because it existed.

Therefore, the performance is the song. Copyright protection for "A Day in the Life" as a composition is meaningless unless the recording is protected too; the composition doesn't exist outside the performance, the case for much post-1962 pop, from "I Can See for Miles" to "Good Vibrations."