(FORTUNE Magazine) – It's the same old copyright song, copied over and over. Only now the volume is getting louder.

The movie studios tried to stop the introduction of videocassette recorders but settled for copyright protection built into videocassettes and DVD players. Cable TV and satellite broadcasters scramble their signals and require decryption cards in set-top boxes to thwart unauthorized viewing. Product-activation codes, like the one in Microsoft's new Windows XP operating system, are the latest in a long series of attempts by software makers to fight piracy of their programs. Television broadcasters are trying to stop ReplayTV from selling a new digital video recorder that connects to the Internet.

But the recording industry, already exasperated by Napster, MP3 digital audio players, and PC-based CD burners, is testing what could be the least popular copyright protection plan yet: a scheme intended to prevent the owner of a new audio CD from playing it in a personal computer's CD drive. Universal Music, the world's largest record company, has vowed to put copy protection on all its CDs within six months. Other labels say they're quietly test-marketing copy-protected CDs in selected areas.

Universal and the other record companies are aggressively trying to stop consumers from "ripping and burning" (copying music to a PC and then onto a blank compact disk) or exchanging the ripped files with other computer users over file-sharing sites like Morpheus, KazaA, and Grokster, which have cut labels and their artists out of the payment pipeline.

Using copy-protection technologies produced by companies like Macrovision, Midbar Tech, SunnComm, and Sony, major record companies and some independent labels are beginning to add extra code to standard audio CDs to prevent the owner of the CD from copying the songs into computer files, or to limit the number of copies, or to deliberately distort and corrupt the music when it's copied to a hard disk.

Unfortunately, some copy-protected audio CDs have the nasty side effect of not playing at all on some car CD players, DVD players, Apple Macintosh computers, or videogame consoles capable of playing music disks, like Microsoft's Xbox or Sony's PlayStation 2.

"I think it is a strategy born out of frustration and a perceived lack of options," says Chris Gorog, CEO of Roxio, which makes software that allows users to burn their own custom CDs. "When consumers pay retail for a brand-new CD and find it unplayable in a lot of their devices, they're not going to be happy."

Copy protection is still in the experimental stage with many labels, but some consumers are already feeling the pain. Universal's European release of Natalie Imbruglia's White Lilies CD uses Midbar Tech's Cactus Data Shield copy protection and has had playback problems on some audio and PC systems. Complaints from users are increasing, perhaps spurred by online protests that urge buyers of copy-protected audio CDs to return them as "defective."

BMG Music says it has had to replace one of every 1,000 CDs issued in Europe. Although the returns are small as a percentage of sales, they are expensive and cause disproportionate bad publicity. (In California, a woman filed a lawsuit against the independent label Music City Records because her new Charlie Pride CD, A Tribute to Jim Reeves, did not have a disclaimer telling her it wouldn't play on her computer's CD drive.)

To some especially technically sophisticated consumers, copy protection falls somewhere between an annoyance and an amusing challenge. "Hackers will make this their obsession and crack it and put it up on Morpheus," says Gorog. "Then what have you accomplished?"

Indeed, programmers start working as soon as a new copy-protection scheme is introduced, and they're almost always successful in breaking the code. An online digital-rights management system developed by Microsoft and adopted by Vivendi and Sony has already been cracked. Similarly, several teenage hackers quickly broke the copy-protection software used on DVD movie disks. Microsoft and other companies that make digital-rights management software acknowledge that their codes are not impregnable, but they contend that any discovered flaws are fixed quickly.

Even if the music industry is successful in restricting the copying of music in the post-Napster era, it's doubtful that the new copyright measures will be a hit with consumers who have become accustomed to playing their purchases on a growing variety of digital devices, including multimedia computers, MP3 players, game machines, networked digital audio receivers, portable CD players, car stereos, and even MP3-enabled digital cameras--not to mention some ordinary CD machines. If the new CD copy protections restrict legitimate uses for the music bought by consumers, the cure for unauthorized copying could turn out to be more damaging than the original problem.

--Mark Borden