Read this: The 20 greatest AC/DC songs – ranked
Noting that the music was there but the lyrics weren't, Angus continues that Malcolm then asked, 'Well, have you got something you can come up with?'
"And I said, 'Okay, give me a few minutes,'" he recalls. "And I went to the toilet, and then I was in the toilet and I was there and I'm sitting and thinking. And I'm just sitting on the throne more or less. And then I go, 'I think I've got it. I've got it. I've got it. I've got the idea in my head.'
"And then I came in there and I said, 'I've got it. Highway to hell.' And I was over the chords that we had tried out through a chorus. And he went, 'Yeah, that'll work.' And he said, 'If we spread it out a bit into full singing thing.' So he came up with a spread of it, '(Singing) Highway to hell.'"
Amazing. See Angus and frontman Brian Johnson chatting about Highway To Hell, Thunderstruck, Back In Black and more in the video below, and hear the full episode on demand over at apple.co/_EssentialsRadio.