2. Revolver pioneered the use of one of the Beatles’ secret sonic weapons.
If there’s a key ingredient in Revolver’s sonic stew, it’s a technique the Beatles and George Martin pioneered called Artificial Double Tracking: ADT, for those in the know. It’s what you hear on “Tomorrow Never Knows,” for instance, when Lennon’s voice goes all extra-terrestrial.
“Artificial Double Tracking is taking an image of a sound and delaying it slightly, or advancing it slightly, so that it forms double,” George Martin said in the Beatles’ Anthology. “If you think in photographic terms, it’s like having two negatives: when you get one negative exactly on top of the other there’s just one picture. So if you have one sound image on top of the other exactly, then it becomes only one image. But move it slightly, by a few milliseconds, and around eight or nine milliseconds it gives you a boxy telephone-like quality.”
Lennon put it more succinctly: “‘Double-flanging’, we call it.”