Because we're talking about SS here, for perfect example, check out half the animated segments, especially Jazz #'s.
But yeah... I know the Beatles experimented, but in all honesty, I don't think they needed it to make their better more experimental music. The common misconception/joke is that someone who does or creates something bizzarre has to be on drugs to create something like it. But the truth is it hamper's your judgement, not inspires it. For me to give a good example of something that seems like it was really done on drugs, look at that Quizno's commercial where the guy can't seem to remember the "letter" to say "MMMMMM" (and says rrrrr and P-p-p-p). That seems like it was made without any effort, it makes no sense, and it only seems funny if you're feeling giggly anyway (so doesn't finding a penny on the floor).