Lots of rock singers sing in a voice that may not be their most comfortable singing voice when they’re trying to sing with a certain edge to fit the sound of the band and the songs they’re performing. Axl Rose’s voice is mostly his falsetto and higher pitched scream than what would be in his normal singing range. Many of Sammy Hagar’s Van Halen songs were higher than he would normally sing. And over time those songs get harder and harder on their voices, and become harder to perform later on in their careers.
Brian Johnson is no different.
In his previous band before joining AC/DC, Geordie, he sang more like Tom Jones, than Bon Scott. Check them out on a German TV show in 1975.
And here’s a side by side to show the difference.
Brian, thank you for torturing your own vocal chords for our enjoyment, for decades!