Lars Ulrich originally set the wheels of Metallica in motion when he placed an ad in an LA paper looking for musicians to "jam with Tygers of Pan Tang, Diamond Head and Iron Maiden". It resulted in the formation of one of the few metal bands to break into the mainstream and stay there as they asserted themselves as one of the world's biggest-selling bands. Initially building a following on the underground LA scene with Dave Mustaine (who went on to form Megadeth) Metallica released two unsuccessful albums before unleashing the influential Master of Puppets in 1986. Overcoming the loss of original bass player Cliff Burton - killed when their tour bus crashed in Sweden - they returned with their self-titled breakthrough album in 1991, which topped the US album charts and has gone on to sell over 22m copies worldwide. They used that platform to achieve even greater commercial success with over 100m albums sold.