Metallica, one of the most prominent hold-outs in the move to online digital music sales, finally relented on Tuesday and added its catalog to the iTunes Music Store. Each of the band's first four albums includes a pair of previously unreleased bonus tracks from a 1989 concert performed in Seattle.

The band said on its official Web site: "Oh, and by the way, the iTunes Music Stores in the U.S. and Canada are the only ones that will be offering Metallica. This is unfortunately due to the fact that our record company overseas doesn't seem to want to play ball with us on this at the moment. Hopefully this will get sorted out ASAFP, [as soon as fucking possible] but we didn't want our fans in North America to have to wait any longer while our overseas record company tries to get their shit together!"

Noting that the iTunes Music Store is an "upstart outfit who we feel may very well have a bright future," the band also said that it made the move because "over the last year or so, we have seen an ever-growing number of Metallica fans using online sites like iTunes to get their music." While Metallica had previously made its albums available for sale online through various outlets, this marks the first time that it allowed its fans to buy digital singles too.

Metallica was one of the first bands to complain about Napster when the site was a peer-to-peer file sharing company. The band complained that it was losing royalties because users were sharing its music that way, and at one point, drummer Lars Ulrich delivered to the company's offices a box containing a print-out of every Napster user who had shared Metallica music, demanding that all of them have their accounts shut down. Napster complied, but it was unable to stop those users from simply creating new accounts.

Some fans were upset over those developments, feeling that the band was unfairly punishing those who had been loyal to it. Others pointed to Metallica's willingness to let fans record their concerts and trade those tapes, saying that the band was being hypocritical. Metallica rebuffed those comments by saying that Napster users were committing copyright infringement and denying band members the royalties they would have received if that music had been purchased legally.

Thanks to iPO reader "Spider" for the heads-up.