Four years since Metallica released 'Death Magnetic,' the band have announced that they will begin to 'concentrate on new music' for their next album beginning in September. Metallica will once again team with legendary producer Rick Rubin to craft the band's 10th album.

During a conference call to discuss the band's headlining appearance at the Outside Lands festival, drummer Lars Ulrich began sung the praises of frontman James Hetfield and his songwriting progress. "Every time James Hetfield picks up a guitar, there are some brilliant riffs that come out of it, and I try to make sure that they are all recorded and try to do my best to keep up with them and try to put some drums in behind them," says Ulrich.

He continues, "So there are, obviously, tons of ideas sitting around waiting to be had at in terms of turning ideas of James' into songs. Pretty much when we're done with the [3D] movie [project] and with Outside Lands, which should all be wrapped up by early September, we're gonna basically just concentrate on new music and try to get another Metallica record [done]."

In a separate interview with Pulse of the Radio, James Hetfield said, "I can't turn off the creative part of me, which is — what a great gift. There's stuff coming out all the time, whether it's in the tuning room, in my hotel room, sitting at home with the acoustic, wherever. The stuff is coming out, and it gets recorded or written down or something, some way, and it'll come out at some point. Whether it's on this album, the next album, who knows."

Metallica's 10th studio album is expected to drop sometime in 2013.