AC/DC’s 7th album was released on 25 July 1980. Their first with singer Brian Johnson, it came out just months after the death of Bon Scott, AC/DC’s previous frontman. Housed in a plain black sleeve, with a new singer and a tragic backstory, Back In Black went on to sell over 50 million copies world-wide to become the best-selling rock album of all-time. But c'mon: is it THAT good?