“The publishers can’t dispute the fact that the popularity of playing guitar has exploded because of sites like mine,” said Robert Balch, the publisher of Guitar Tab Universe (guitartabs.cc), in Los Angeles. “And any person that buys a guitar book during their lifetime, that money goes to the publishers.”

Image Credit... Illustration by The New York Times

Mr. Balch, who took down guitar tabs from his site in late July at the behest of the music publishers, added that, “I’d think the music publishers would be happy to have sites that get people interested in becoming one of their customers.”

Cathal Woods, who manages Olga.net, one of the pioneer free tablature sites, said he had run the site for 14 years with the help of a systems administrator, “and we’ve never taken a penny.” Mr. Woods, who teaches philosophy at Virginia Wesleyan College in Norfolk, said Olga.net had earned an undisclosed amount of money by posting ads on Google’s behalf, but he said that money had paid for bandwidth and a legal defense fund.

Anthony DeGidio, a lawyer for Olga.net, said he was still formulating a legal strategy, while also helping decide whether the site could pay licensing fees “in the event that that’s required.” For now, though, the site remains unavailable to users.

Because the music tablature sites are privately held, they do not disclose sales figures, and because industry analysts generally do not closely follow tablature sites, it is unclear how much revenue they generate. But with the Internet advertising market surging, almost any Web site with significant traffic can generate revenue.

Google also dabbles in tablature through its Google Groups discussion board service, in which guitar players trade tabs they have figured out by listening to the songs, or by copying tabs found elsewhere. A Google spokesman, Steve Langdon, said Google would take down music tablature from its Groups service if publishers claimed the materials violated copyright agreements and if Google determined that infringement was likely. Under the Digital Millennium Copyright Act, Web hosts may review, case by case, a publisher’s claims regarding instances of copyright infringement.