Metallica frontman James Hetfield has apologised to the band's fans for releasing so few albums throughout their career.
The rock legends have been active for more than a quarter of a century, but have just eight albums to their name - a ninth is forthcoming.
Hetfield tells, "We're slow. Metallica's clock is very slow. It's unbelievable. Most bands hit their 9th album after 12 or 13 years. We've been together for 26, 27 years."