Jethro Tull 5

AC/DC are in, Deep Purple aren't and you cannot understand why Tull aren't there. With that sort of logic it's a wonder some of the worthies even made it in. I'm an Aussie, like but don't love AC/DC yet their induction baffles me.
It has been stated that Atlantic records artists are disproportinately represented. I don't know if it is true but guess which label AC/DC were on at one stage?