I've learned by ear since I was young. Recently I started scale study and realize that I'm already doing a lot of things, or bits of particular scales. Still, I prefer to learn by ear in the context of a song so I get the emotional connection. So I'm hoping to get some examples of scale usage in songs. I don't think solo's stay in one specific scale, but i'm sure there are examples where those who know can say "the riff in XXX tune is largely XXX scale"?