 The term was first used in music in Steppenwolf's "Born to Be Wild" (1967) and began to be associated with pioneer bands like San Francisco's Blue Cheer, Cleveland's James Gang and Michigan's Grand Funk Railroad.By 1970 three key British bands had developed the characteristic sounds and styles which would help shape the subgenre.Led Zeppelin added elements of fantasy to their riff laden blues-rock, Deep Purple brought in symphonic and medieval interests from their progressive rock phase and Black Sabbath introduced facets of the gothic and modal harmony, helping to produce a "darker" sound.