The Offspring's metal-inflected punk became a popular sensation in 1994, selling over four million albums on an independent record label. While the group's credentials and approach follow the indie rock tradition of the '80s, sonically the Offspring sound more like an edgy, hard-driving heavy metal band, with their precise, pulsing power chords and Dexter Holland's flat vocals. Featuring Holland, guitarist Kevin "Noodles" Wasserman, bassist Greg Kriesel, and drummer Ron Welty, the Offspring released their self-titled debut album in 1989.