Before the middle 60s, the preferred sound for electric guitars was clean and pure. Sure, there were exceptions–Link Wray, Dick Dale, the Kinks–but they were the crazy ones, people who would rewire their amps or cause deliberate damage to speaker cones to create some kind of distortion. But this fuzziness was unpredictable. Getting the same degree of fuzziness song to song and day to day was difficult, if not impossible.
It wasn’t until the introduction of distortion pedals that things began to change. This was a device inserted between the guitar and the amp that could reliably deliver the desired amount of distortion on demand. One of the very first was the Maestro Fuzz-Tone FZ-1, which, at first, was a roaring failure. ZERO units were sold in all of 1964. It wasn’t until Keith Richards decided fuzz up his guitar from the Rolling Stones song “Satisfaction” in 1965 that the idea of a fuzz pedal began to catch on.