Pete Townshend's guitar smashing came about by accident. While playing a club gig, Townshend banged his guitar against the low ceiling cracking the body. Since the guitar was now useless, why not smash it to bits. So he slammed it into the stage, with splinters flying about. He didn't really give it another thought, except trying to figure out where he was going to get the money for a new guitar. The audience's reaction was another matter. Fans came up after the show excitedly talking about the destruction. Townshend was on to something. Soon the guitar demolition, along with Moon's kicking over his drum kit, became an integral part of The Who's concerts - until Townshend got tired of doing it and quit.
Given his naturally theatrical nature, Townshend's 'windmill" guitar fit perfectly. His arm would turn in a violent circular motion with his fist (holding a heavy gage pick) crashing into the strings creating an earth shaking sound. After all, The Who was one of the loudest groups of all-time.
While not lightening fast, Townshend used the guitar for dramatic effect. Riveting chord progressions and single note blasts mark all great Who songs. "I Can See For Miles," "Pinball Wizard," and "Won't Get Fooled Again" all rely on Townshend's percussive guitar which added to the group's rhythmic punch. He may or may not have invented it, but Townshend was certainly an early practitioner of the power chord.
As The Who's primary songwriter, Townshend excelled, not only composing the group's hits but managing to create the only successful Rock opera, "Tommy."
Starting as a fairly routine R & B influenced guitarist, Townshend developed his own style, not by playing more but often playing less, only more powerfully. In that capacity, Townshend laid the groundwork for Heavy Metal.
See The Who.