Mastodon is an American heavy metal band from Atlanta, Georgia. Formed in 2000, the group is composed of bassist Troy Sanders, guitarists Brent Hinds and Bill Kelliher, and drummer Brann Dailor. They discovered they had a mutual appreciation of sludge metal bands Melvins and Neurosis and 1970s hard-rockers Thin Lizzy, and shortly thereafter formed Mastodon. Their musical style features progressive concepts and unique instrumentation. Mastodon has released seven studio albums, as well as a number of other records.