AC/DC’s third album, released in Australia in 1976, wasn’t released internationally until 1981, and when it was, the track listing was shuffled (“R.I.P. (Rock in Peace)” and “Jailbreak” were cut, and “Love At First Feel” and “Rocker” added). But the three key tracks — the title song, “Problem Child,” and “Ain’t No Fun (Waiting ’Round to Be a Millionaire)” — are included on both versions. This was AC/DC at their most snarling and sneering, outdoing the punks in attitudinal terms while giving blues-rock fans a ferocious boogie to jump up and down to. And frontman Bon Scott was always an underrated lyricist, mixing smart-dumb sex jokes with the rage of a poor man staring at people who looked down on him even though they had nothing going for them but their money. AC/DC had the riffs, the beat of Phil Rudd’s ultra-minimalist drums, and a focused worldview. They were unstoppable.