Headbangers, rejoice.

Hard rockers Metallica have given in to popular demand, finally agreeing to allow their individual songs to be downloaded via Apple's iTunes Music Store.

The group had previously allowed whole albums to be bought online through other retailers and its own website, but they'd always resisted selling individual songs through iTunes.

Now fans of the heavy metal pioneers can pick and choose which tracks they want for $0.99 apiece, or purchase full albums. They're offering up songs from four albums - Kill 'Em All, Ride The Lightning, Justice for All and Master of Puppets.

The band conceded, in an online message, that its fans were increasingly buying their music online and said they sweetened the deal for those who already own copies by adding previously unreleased live tracks to each of the albums.

The 'new' material was actually recorded in 1989 in Seattle.

Several years ago, Metallica joined with other artists in challenging online file-sharing service Napster.

And though the rockers have now embraced iTunes, there are still a number of artists refusing to sell through the Apple store including Led Zeppelin, the Beatles, and Radiohead.