I first read about the supernormal stimulus in one of Joseph Campbell’s books where he was explaining religious psychology in terms of the captivating power of exaggerated attributes. He cited Niko Tinbergen’s observation that a male grayling butterfly will try to mate with a cardboard model rather than a real female if the artificial substitute is darker colored. Foolish butterfly! Foolish humans, to believe in gods!
But if we’re talking just about aesthetic experience, we could hardly settle for less than supernormal. Only too much is enough.
Music itself is supernormal to start with, involving better-than-natural voices, but inside music there can be a super-supernormal stimulus, thanks to electrification, and the most conspicuous one to me is an extremely warm, pure, strong-sounding guitar tone heard in individually struck notes. “Strong-sounding” implies wide frequency activity and probably some delay. The “pure” part is important: no resorting to gritty timbre, no screaming or scratching to get our attention. It just glows like gold.
What is the normal value that gets artificially one-upped by the huge guitar tone, a value that is somehow already strong inside us? It’s got to be something primal. It’s got to have the beauty of the lady butterfly, so to speak. How about this: like hearing a lush chord can seem even better than being enfolded by your mother’s body, hearing this guitar tone can seem even better than hearing your father’s voice speaking from up close.
Be that as it may, here are some cases where a huge guitar tone takes a song over and takes charge of your life. You can only do the listening equivalent of gaping at it. (But notice the importance of relatively low notes, and think about your real or mythic father.)
This train of reflection started while listening to a Steve Earle track, so I’ll work backward from there.
Steve Earle, “Hillbilly Highway” (1986)—Richard Bennett, guitar
The Soft Boys, “Kingdom of Love” (1980)—Kimberly Rew, guitar
Linda Ronstadt, “You’re No Good” (1974)—Andrew Gold, guitar
“You’re No Good,” starting with second verse
And the multi-tracked monster:
The Beatles, “I Want You (She’s So Heavy)” (1969)—John Lennon and George Harrison, guitars
Here’s another case of huge guitar tone that I don’t think is “pure” enough to be in this reference set, and yet it sort of belongs, too, in its single-minded domineering, so I include it in the exhibit to encourage discussion of what “pure” actually is, in this context, or whether it is.
Queen, “Play The Game” (1980)—Brian May, guitar
 Joseph Campbell, The Masks of God, vol. 1: Primitive Mythology (New York: Penguin, 1969), pp. 42-44. More recently, see Deirdre Barrett, Supernormal Stimuli: How Primal Urges Overran Their Evolutionary Purpose (New York: Norton, 2010).