The no-nonsense power chord blast that signaled the arrival of Australian band AC/DC, became one of the most influential hard rock sounds of the '70s. It is a formula that has remained essentially unchanged for more than 30 years and one that has brought them Worldwide success and renown. Although the band are most often classified as hard rock, and considered to be early pioneers of heavy metal, they have always resolutely defined their music as good ol’ rock and roll.