Angus Young revealed that both the last AC/DC album and its upcoming studio set were both culled from boxes of unused riffs. While appearing on Dean Delray's Let There Be Talk podcast, Angus explained that the band's upcoming album Power Up was created by sorting through the reels of tapes featuring him and late-brother Malcolm Young riffing in their home studios.
Angus explained that he presented numerous boxes of rough musical ideas to producer Brendan O'Brien, who helped him sort out which to choose as the basis of the new songs: “A lot of these songs, when we were going to do the album Black Ice, Malcolm and me had a lot of years where the two of us would just be in, y'know, a little studio just workin' away all the time — just writing songs. And in the period with so much stuff, even when we went to do Black Ice, it was a case of, y'know, you've got a few boxes of your ideas. . . And it was a case of — we only got even to box one! And we were just pulling out the first stuff that we had of tracks. Y'know, by the time you've got that, you've got, like 20 ideas.”