Earlier I referred to a sentence in MOJO from their analysis of Pet Sounds. Found it in the second paragraph of the piece.
"Recent exposure to heavy doses of LSD-25 had also boosted Wilson's interest in mind-expanding music that would affect people on a deeper level."
"From an aesthetic point of view, psychedelic art must be defined as that art which deliberately attempts to re-create, introduce, stimulate or convey the nature or essence of the psychedelic experience. Unless psychedelic art is defined as the conscious expression of the psychedelic experience, "anything presented as a work of art that inspires the mind, emotions and sense with even a glimpse of the total awareness of conscious being could be termed psychedelic art", according to Jud Yalkut, writing in Arts magazine. Which is to say that all art then becomes psychedelic; or that the term is lost to the semantic chaos that already hovers over much of modern art."
- Barry Schwartz in "Psychedelic Art" (1968)
Barry Schwartz's definition is the true test of whether or not a piece of art is psychedelic art. If Pet Sounds is psychedelic then it is,
"art which deliberately attempts to re-create, introduce, stimulate or convey the nature or essence of the psychedelic experience."
Brian's LSD use led to a growing spiritual awareness which went hand in hand with strong feelings of love, and a greater awareness of love. Pet Sounds was made with a goal of communicating these aspects of the psychedelic experience to the listener. Because of this I think Pets Sounds qualifies as psychedelic art.
"This, I thought, could be the beginning of a new type of sophisticated-feeling music."
"I was in a loving mood for a few months and it found its way to recorded tape."
"I experimented with sounds that would make the listener feel loved."
On Pet Sounds Brian Wilson wanted to create something that would be considered "a good piece of love, of spiritual love."