An American sludge metal and alternative metal band based out of Atlanta, Georgia. Founded in 2000 after its members — bassist/singer Troy Sanders, lead guitarist/singer Brent Hinds, rhythm guitarist Bill Kelliher and drummer/singer Brann Dailor — met at a High on Fire concert. Known for sludge metal with a progressive element that also is accessible, Mastodon rose to popularity behind three successive concept records during the 2000s. In the 2010s, the band found itself cleaning up its vocals and production while still trying to retain some of its former gusto.