4. "A Quick One, While He's Away" ('A Quick One,' 1966)
By late 1966, Townshend had been churning out thrilling singles for nearly two years. But he was anxious to try something that broke away from the structure of pop altogether. He wound up writing a nine-minute opus that was dubbed a "mini opera," divided into six distinct parts, about a woman who misses her absent lover and winds up cheating on him with a bloke named Ivor the Engine Driver. The song incorporates everything from folk to blues to country to pile-driving rock & roll. The Who wanted to hire cellists to play near the climax, but due to budget shortfalls they wound up merely chanting the word "cello" over and over again to glorious effect. The hilarious, frenetic results were unlike anything else in 1966, though it wasn't until years later that Townshend saw a deeper meaning. "It is the story that many of us postwar kids share of being sent away," he said in 2012. "And of losing a precious loved one and being greatly changed when they returned."