The world's massed bands of bedroom guitarists have been enjoying themselves more than usual of late. The growth of the internet has made sheet music freely available, putting even the trickiest Jimmy Page solos within the reach of the average guitar picker.
But a concerted legal effort in the United States, which is about to gather pace, could spell the beginning of the end for free music on the Web.
Some analysts think the industry is squaring up for a rerun of the costly and damaging legal battles with peer-to-peer file-share services such as Napster in 2000 and 2001.
And music fans are talking about an ugly new wave of corporate censorship.
Most popular sites feature guitar tablature - a simplified notation with numbered finger positions on the fretboard rather than the crotchets and quavers of traditional notation.
The chords for almost any pop song, from Jimi Hendrix's "Hey Joe", to Eric Clapton's "Layla" or Guns n' Roses' "Welcome to the Jungle" can be found by tapping the title into a search engine. Scores for classical music are also starting to end up online.
In the US, the most popular guitar tablature books would sell 25,000 copies in the early 1990s. Today that figure is closer to 5,000, said Lauren Keiser, the president of the New York-based Music Publishers Association (MPA).
Sheet music publishing in Britain is worth around £50m a year, revenues which could be slashed as customers migrate to the free internet sites.
Many of the sites are supported by big advertisers, even though the content was legally questionable, noted Stephen Navin, the chief executive of Britain's Music Publishers Association (no connection).
"People are clearly making money out of this so it makes me think 'why can't we make some too?' I want to engage these people positively," he said.
While British publishers take this conciliatory line, and have yet to move against any websites, in America, the MPA and the National Music Publishers Association (NMPA) have been markedly more aggressive.
Since last summer, they have been trying to shut sites, including some of the most popular, such as Guitar Tab Universe, which is based in Los Angeles. So far, 21 American sites have closed after receiving letters warning them they were infringing the songwriters' copyrights. Those which ignore the letters could face legal action.
Site operators have responded by removing the music while issuing belligerent statements in defence of their position, insisting that the big industry players are stamping on fans' freedoms.
But Jacqueline Charlesworth, the vice-president of the Washington DC based NMPA, said the campaign was focusing on commercial profit-making sites.
"A lot of people who sit down and transcribe these songs by listening to them and putting them on a website do not think they are infringing copyright," Ms Charlesworth said.
"But when someone writes a song, the rights to transcribe it belong to the songwriter," she said.
"Song writing is a difficult and uncertain profession," she said. "Most songwriters suffer financially. It's tough. You can have a hit and still not get rich. It is important to us that songwriters get paid."Reuse content