Chris Stamp and Kit Lambert, without whom Pete Townshend might never have smashed a guitar.

Chris Stamp and Kit Lambert, without whom Pete Townshend might never have smashed a guitar.

All Kit Lambert and Chris Stamp wanted was to make a movie.

The fate of this pair of would-be impresarios was sealed in 1964, when they decided to make a documentary about a West London rock ‘n’ roll group. Thanks largely to their intervention, the band they set their sights on became the Who, and Lambert and Stamp became two of the most notorious—and ingenious—rock managers in a field crowded with the likes of Brian Epstein, Andrew Loog Oldham, and Robert Stigwood. With the release of Lambert & Stamp, a brilliant, wholly absorbing documentary about the managers’ partnership and the era that fed and was fed by it, the circle is complete…