The legendary British quartet's entire back catalogue has been remastered and cleaned up, while the Fab Four appear in "The Beatles: Rock Band", which is tipped to become one of the world's biggest selling games.

Five million albums have been shipped to stores across the world, reports said, and retailers are bracing themselves for a wave of fans eager to snap up copies of the music and game.

Pre-sales indicated that the release of the albums was on track to be "the biggest catalogue reissue ever conducted in the history of the music business," record label EMI's Ernesto Schmitt told the Financial Times.

The Beatles' company Apple Corps has historically shunned releasing their music in digital formats due to piracy concerns.

But "Rock Band" players will be able to download entire albums in the coming months as the 1960s icons catch up with 21st century technology.

The Beatles' back catalogue was first released on compact disc in 1987, though many fans felt the sound quality did not match the original vinyl, while technological advances since then have highlighted flaws and imperfections.

The new versions include the group's 12 albums, plus the "Magical Mystery Tour" soundtrack and the "Past Masters" releases covering non-album singles.

Some are tipping them to dominate the charts around the globe.

Two box sets are also being released: one in stereo and the other in mono.

The albums are those released in Britain, and retain the original artwork and track listings.

The first 50,000 box sets in mono -- costing 170 pounds (193 euros, 280 dollars) -- have sold out in Britain, said EMI executive Schmitt.

It is the first time that the group's first four albums -- "Please Please Me", "With The Beatles", "A Hard Day's Night" and "Beatles for Sale" -- have been released on compact disc entirely in stereo.

The albums were digitally remastered over a four-year period at Abbey Road Studios in London, where The Beatles -- lead guitarist George Harrison, rhythm guitarist John Lennon, bassist Paul McCartney and drummer Ringo Starr -- recorded most of their music.

The Fab Four have been recreated in virtual forms in "The Beatles: Rock Band", a game that lets players join the band as they springboard from gigs in their native Liverpool, northwest England, to global stardom.

At the launch of the game Tuesday at Liverpool's Cavern Club -- where the Beatles performed in the early 1960s -- fans strummed plastic guitars, kept the beat on a drum kit and sang along as they tried to emulate their idols.

Forty-five songs are included with the video game, and more of the bands' tunes will be sold as digital downloads from the Internet.

"How wonderful that The Beatles' legacy will find its natural progression into the 21st century through the computerised world we live in," Starr has said. "The game is good, the graphics are very good -- and we were great."

(c) 2009 AFP