It may seem like gobbledegook to the uninitiated. For guitar players, however, internet sites such as olga.net, tabplanet and tabrobot provide a wealth of free chords and lyrics to tens of thousands of pop songs.

So should you wish to entertain the relatives with U2's "New Year's Day" (G, A minor, G, F, A minor, C, E minor), it is there for the taking. Ditto songs by George Harrison, The Doors, White Zombie or - whisper it quietly - the Vengaboys.

They claim that their millions of fans are simply swapping their own interpretations of popular songs. But these websites - and there are dozens of them - have stepped on the wrong side of the law. By giving away musical notation, they are abusing the copyright of the artists who wrote the songs and their record companies.

"The problem has been around for a long time in the form of photocopying," says Mark Munford of Net4Music.com, a legitimate sheet-music seller. But there is a huge gulf between photocopying your friend's meagre stash and accessing thousands of songs on the net. "It is theft, robbery," says Chris Butler, general manager of Music Sales, the UK's largest publisher and retailer of pop sheet music.

The situation bears all the hallmarks of Napster, the website which allowed members to exchange MP3 files (audio music) over the net until caught on the wrong side of the law. The only difference is the scale. In the UK, the legitimate sheet music publishing business is only worth £42m a year.

Just as Napster was forced to toe the line, the same is happening to the music publishing websites. Olga (On-Line Guitar Archive) was the victim in 1998 of legal action by the Harry Fox Agency, which represents the National Music Publishers' Association in New York. Forced to go offline, the archive was resuscitated a year later in a much milder form.

Olga is now a non-profit organisation and only offers chord structures with very few lyrics for guidance. A team of 20 volunteers combs the archive, searching for songs that are still breaking the law. The sanitised site now has 20m hits a year - a fraction of its peak three years ago. Other sites have been closed down (nutz.com, for example), bought up (lyricfind.com) or generally brought into line.

However, the legalities are far from over. "I'm sure they cannot get away with claiming they can legally publish [just] the chords," says one copyright lawyer.

Tim McEwan, the 23-year-old general manager of Olga, wants to co-operate with the music industry. "We have started researching if we can resell for existing sheet-music sites, and we may even offer CDs by working with the record companies," he says.

As a non-profit organisation, however, what would Olga ues the money for? Building up a legal fund, explains McEwan, demonstrating that the old defiance is still there. "We would welcome a definitive test case. We would like to see it in writing one way or the other."

The pirates claim that their sites encourage more people to play the guitar, providing more customers for the legitimate sheet music publishers, whose sales in the UK flat for 10 years.

Classical music publishers fear no threat from the internet. Boosey & Hawkes has started a small internet business selling classical tunes which can be downloaded for a fraction of the usual price. However, it will remain a side business, according to Stephen Richards, director of print music at the company. "Musicians looking for performing editions will want something solid that sits on the piano with editorial marks, not just a few bits of paper," he explains.

It is the pop side of the business that detests the pirates. Music Sales is the UK's biggest player. Not only does it own 150 or the country's 1,500 music shops, but it also publishes for Sony, Universal, BMG, Pink Floyd and others, and sells online.

The theory that Olga has gone legitimate cuts no ice with Butler. "It's a bit like breaking into someone's holiday home, getting someone else to stay there for a few weeks for money, and then offering to share the cash with the owner," he says.

Although he cannot prove that Music Sales has lost turnover because of the free websites, he comments: "To say my sales have not fallen over 10 years is not much of a business plan. We are supposed to be driving growth forward and we are not."

It is common knowledge that there are still dozens of renegade websites out there. At one point there were more than 40 servers offering the same content as Olga, known as "mirror" Olga sites, some of them in countries not under US copyright.

The global nature of the internet also makes policing difficult, adds Sarah Faulder, chief executive of the UK's Music Publishers' Association. "A lot of sites are based in the US and we cannot really deal with them over there," she admits.

A new voluntary initiative among the ISPs called Rightswatch is hoping to crack down on all copyright infringements. But the way ahead is not easy.

"We cannot compete with price zero - it is a very compelling price," says Butler. "And finding these pirates is like nailing jelly to the wall in the middle of the night. They are neither visible nor accessible."

jamespickard@hotmail.com

www.olga.net