While Cher’s Believe was notably the first example of extreme digital Auto-Tune used in a chart-smash, vocal manipulation in the context of pop goes back a long way. Even prior to Kraftwerk’s pre-eminent use of the vocoder, way back in 1939, Bell Labs’ Homer Dudley created the ‘Voice Operating Demonstrator’ – essentially a synth for the human voice that could limit the bandwidth required for military communications in World War II. Though he wasn’t aware at the time, he’d created the prototype of the vocoder. These principles were applied by such pioneers as Robert Moog and Wendy Carlos on their influential A Clockwork Orange soundtrack, and by the BBC’s Radiophonic Workshop in the ’70s. But, even back in the ’60s, groundbreakers like The Beatles pushed the vocal envelope in pop. On the fab four’s epic closer to 1966’s Revolver, John Lennon’s vocals were run through the Leslie speaker of a Hammond organ, creating a shimmering tremolo effect. Just one element that made Tomorrow Never Knows so innovative. Slap delays, wrought from tape bouncing, were also common in this period, and added depth to a vocal’s timbre.