To my mind, there are two forms of psychedelic music.  In the first, the artist/musician attempts to recreate or simulate the effects of the psychedelic experience.  Yesterday's Miles Davis composition is an example of this form, with its disassociation of time and space and the way it loses itself in layers.  These artists are saying, in effect, "this is what it was like when we were high." 

Today I'm talking about the other form of psychedelic music, which is produced by the artists/musicians who use the expanded consciousness afforded by the psychedelic experience to express something that may not have been realized without that experience.  These artists are not saying, "this is what it was like when I was high," but are instead expressing ideas, concepts or emotions that have been informed by the experience (e.g., "This is what love is about when ego/self has been transcended").  

Much of Bjork's music and art falls into this latter category.  The video above is not some sort of recreation of what it's like to be tripping, but could only have been conceived by someone who had.

Which is not to say that the only way to be creative is to get stoned out of one's mind.  One of my pet peeves is when I hear someone who's seen some art or performance that is truly creative or even downright weird state, "That person must have been on something really wild," as if that's the only possible explanation for ideas or conceptual creations outside of the norm.  This is not only demeaning of the originality of creative artists, but it shows the limited imagination of the person making the comment.

It's apparently hard for those who haven't undergone the psychedelic experience (or for that matter, those who haven't spent time in intensive meditation) to distinguish between the creative art of the experienced (for lack of a better term) and the inexperienced, but those who have can easily perceive the difference. Those who have can instantly recognize the shared experience expressed by the music of, say, Jimi Hendrix and the band Animal Collective, or for that matter Bjork  They also know without being told that some other musicians, no matter how bizarre or extreme the music may be, don't share their experience (e.g., Frank Zappa and many hardcore metal bands).

An interesting exception to this thesis is David Lynch, who produces both forms (re-creative and reflective) of psychedelic art (in his case, cinema) informed not by psychedelics but by transcendental meditation.  Meditation is not the same as psychedelics and the two don't feel even remotely similar to each other, but both apparently transport the practioner to the same place.

I still don't know how to classify the poetry of Walt Whitman into this scheme.