If, as that multi-part BBC2 documentary once maintained, there were seven ages of 20th century rock music, then The Who are the bridge between eras two and four. Essentially they were a West London beat group, forged in the same crucible as the Stones and the Kinks, who enjoyed a brief mid-1960s fling with psychedelia, fashioned the first "rock opera" (Tommy, 1969), and then emerged blinking into the post-Woodstock glare as the world's heaviest exponents of over-amplified Sturm und Drang.
What allowed them to sustain this impetus into the Seventies and beyond was the song-writing (and organisational) skills of their guitarist Pete Townshend. Without him, The Who would scarcely have existed. With him, the ride would never be easy, and if some of the tensions that undermined the band can be ascribed to the three other founding partners, then quite a few are down to Townshend himself.
Most rock memoirs – and Who I Am is a winningly candid example – weave variations on the chicken-and-egg debate. Does the music business damage the personalities of the people who work in it, or does it merely attract people with damaged personalities and damage them further? Here, nature and nurture zealously combine.
Townshend, tricky childhood behind him, popular music wired into his consciousness by a dance band-ornamenting dad, was an archetypal mixed-up Sixties kid. Drummer Keith Moon and bass player John Entwhistle were career hedonists, who once paid a girl $100 to infect Townshend with gonorrhoea on the premise that he was too strait-laced around the groupies. Vocalist Roger Daltrey, outwardly the sanest of the four, was a hard-boiled but insecure Mod from Acton, scathing of pretension, who once knocked his guitarist out cold after waiting 48 hours for the stage tapes of their 1973 album Quadrophenia to arrive at the recording studio.
What follows is a version of that elemental music pageant in which one person in the group has the drive and the talent while the others follow his lead, annoying him with their regular guy-dom and being annoyed in their turn by his moods and affectations: the story of The Kinks, of The Jam, only with more drugs, death and mayhem.
Having established the band as early 1970s behemoths, against a backdrop of profit-sapping chaos, Townshend runs through the full menu of rock-star trauma, finds God, goes manic-depressive and stages titanic drinking contests with the roadies, while striving for a brand of self-expression that will reveal "the essence of rock itself". The concepts get more abstract, and come the rehearsals for the abortive Lifehouse project in 1971, Daltrey, Moon and Entwhistle are bewildered onlookers. It is left to the veteran Sixties scene-sweller John "Hoppy" Hopkins to assure him, "This is radical, Pete".
By Quadrophenia, the original charge had gone. Later material often sounded like Townshend solo albums in disguise. Moon auto-destructed in 1978, with Entwhistle following in 2002. If a glance through Townshend highly diversified later career (film projects, publishing, multi-media) suggests that his best work was done in his twenties, the same can be said of many a lyric poet. His autobiography is a deeply felt and rather dogged performance, full of fretful self-analysis, anguished status-broking (although Townshend's claim to have "invented the power chord" might be contested by, say, Link Wray) and interesting period detail, such as the West London cleaning ladies wanting to inspect the marriage certificates of "trendy young 60s couples" before they set to work.
Elsewhere, the descriptions of female company met along the way ("her breasts firm and proud under the thin fabric"…) invariably raise a smile, and one had an idea that that George Formby, who the youthful Pete – not a fan - recalls "plucking away at his silly little banjo", actually played the ukelele.
"Pop music was evolving, becoming the barometer for a lot of social change," writes Townshend of the Sixties maelstrom. There are several intensely fascinating moments when he picks up the pop-sociology baton first wielded by the late Ian MacDonald in his Beatles book Revolution in the Head and looks as if he might give it a flourish of his own, but not nearly enough. For all its candour, Who I Am has to be filed under "missed opportunity".
DJ Taylor's latest novel is 'Secondhand Daylight' (Corsair)