Flexing your Grandad credentials here Icy.
having recently spent some time 'being Trevor Bolder' I can confirm there is a lot more to 'simple blues' than meets most ears
There's a lot of BOwie stuff that sounds simple, but is far from, extremely clever arrangements and additional orchestrations . . . .Mick Ronson . . . . . . Steve Miller is another good example, sounds like 3 chords . .but. . . .