Metalica have revealed that they will have to relearn some of their classics for their headline slot at next year's Download Festival.
The band will play their 1991 self-titled fifth album in its entirety at the festival.
The band, who released their collaboration with Lou Reed, 'Lulu,' on October 31, played their classic 1986 album 'Master Of Puppets' from start to finish at the festival in 2006.
Speaking about the show drummer Lars Ulrich told Kerrang!: "The people at Download asked. It wasn't our idea.
"The thing is, although we haven't played at Donington for six years, we have been to the UK pretty much every single summer since then."
He added: "So they wanted us to do something different, and that's what they came up with. I quite like the fact that come next summer it'll be the 21st anniversary of The Black Album, not the 20th."
Ulrich revealed that there are a number of songs from 'The Black Album' - 'Don't Tread On Me' and 'The Struggle Within' - that they have never played live before.
Asked whether they would have to relearn them, he responded: "Yeah. Although to be honest with you, a song like 'The Struggle Within' is a lot easier to relearn than 'The Frayed Ends Of Sanity'.
"I don't think it's going to be too difficult for us to figure out these songs."
The three-day event gets under way at Donington Park from June 8-10 2012.