Are you sure about Buckley? Heroin?
Drugs expand your perception, it can be helpful, but within reason... or maybe not... maybe you should freak out (with or without drugs) and be a bit crazy to make something really classic...
There are many "sober" or "clean" classics, too, just not so many in jazz and rock'n'roll...
And also - I am quite sure that they performed and recorded in the more or less sober state - at least most of them...
Even most of Grateful Dead and Hendrix studio albums, I guess - you cannot play on such a level under acid...
So to add at least
Miles Davis - Bitches Brew
Grateful Dead - everything
The Doors - everything
Honestly - I am not a regular "abuser", but I hardly know a musician that doesn't smoke pot. It just does things to music perception that would be foolish
not to experience from time to time... What do you think? But I have never seen anyone perform satisfactory while being stoned - feeling good, yes, but if you record it - not something special most of the time. But having that "expanded" experience and transfering it later in the sober state into art - that's what usually works fine. I am not so "experienced" though.
