In the telling of rock’n’roll history, managers rarely claim centre stage. That is about to change with a documentary about the relationship between Kit Lambert, the aristocratic, homosexual son of the classical composer Constant Lambert, and Chris Stamp, the son of a tugboat captain, as played out through the creation and management of the Who.

The band has never shied away from crediting the pair – described by singer Roger Daltrey as “the shell of the egg” – but their role in guiding the group from their early days as guitar-smashing mods to their peak of 70s rock indulgence has never been examined so clearly.

The documentary, called Lambert & Stamp, is a reminder of the energy of social upheaval that found expression in pop music. “We were both marginalised, him in gayness and me in my class,” Stamp, who died in 2012, tells the film’s director, James D Cooper. “It was a powerful bond defined creatively in the Who.”

Described by his brother, the actor Terence Stamp, as “a rough, tough fighting spiv”, Stamp and the Oxford-educated Lambert had sought careers in film. Lambert had already been a cameraman on an expedition to the Amazon during which the party had been ambushed by natives and one of their number killed.

The pair resolved to make a film about a band in the documentary style of the French New Wave. What they found in the Who – “four complicated, difficult guys”, Stamp recalled – met their needs. They filmed several concerts, but later abandoned the film and became the band’s managers. Stamp says: “We didn’t know what we wanted, but we knew what we didn’t want. It was really about us – some mad concoction of stuff that looked like us.”

While Lambert encouraged the band’s destructive antics, he also provided them with intellectual cover. Sections of Lambert & Stamp are taken from their would-be documentary and Lambert is filmed philosophising about the era’s “beautiful and powerful” youth.

“Nobody knows for sure where they are going. In 20 years, these young revolutionaries could be arch-conservatives. But not me,” he says.

As Andrew Motion noted in his biography The Lamberts, Kit fashioned the Who so that they would speak for their audiences’ own sexual feelings.

Lambert later said: “They have to have a direct sexual impact. They ask a question: do you want to or don’t you? And they don’t give their public a chance of saying no.”

The cost of the band’s routine destruction of their equipment – encouraged by Lambert – necessitated new streams of income. They turned to recording and established Track Records, the label that signed Jimi Hendrix and the Crazy World of Arthur Brown to its roster.

Lambert fostered Pete Townshend to become the band’s resident composer, instilling him with confidence to reach for grander goals, among them the rock operas Tommy and Quadrophenia. Townshend says it was Lambert who understood the band’s audience. “You don’t give them what they want – you allow them to be,” the guitarist says. “You don’t try to change them – you affirm them.”

Lambert & Stamp is not the only project looking at the role of managers at the time when the rock’n’roll business was still forming. Mojo magazine editor Pat Gilbert, and Orian Williams, producer of the Joy Division biopic Control, are working on a feature film of Lambert’s life that is expected to start filming later this year. “Rock management was a new profession, and an interesting thing for forward-thinking people to get into,” Gilbert said.

Robert Fearnley-Whittingstall, a contemporary of Lambert’s in national service and university, recalls that Lambert was interested in the Who from a creative point of view. It was Lambert who suggested Daltrey’s stutter on My Generation to mimic young fans on amphetamines. “He was a bit self-conscious standing there in a suit, but I think he found there wasn’t such a gap between them.”

While managers such as Elvis Presley’s Colonel Parker, the Sex Pistols’ Malcolm McLaren or Led Zeppelin’s Peter Grant became well-known, their influence is not always clearly acknowledged. Among the forthcoming studies is Barney Hoskyns’s Smalltown Talk, a portrait of Albert Grossman’s creation of the Woodstock music scene in the 60s.

Groups tend to be a reflection of their managers, Yardbirds, T-Rex and Wham! manager Simon Napier-Bell acknowledged to the NME in 1984: “The Beatles were really Brian Epstein’s brushed-up, middle-class gay presentation of some pretty rough boys, and Jagger was so fascinated by [Andrew Loog] Oldham’s campness that he started adopting his mannerisms. The Who were of course an extension of Kit Lambert’s manic attitude to life.”

Lambert’s life rose and disintegrated chasing these visions. His wayward lifestyle contributed to both him and Stamp being sidelined by the band in the mid-70s. His London home burnt down; and his palazzo in Venice was also damaged by fire. Clearly unfit to manage his own affairs, he was made a ward of court to escape a prison sentence after being arrested for drug offences.

“Life was not good,” recalled Fearnley-Whittingstall. “Everyone said he was bankrupt. He said he was owed a lot of money from publishing. After his death [in 1981] that was found to be so.”

Lambert and Stamp may now begin to acquire equal standing with Epstein and the other behind-the-scenes architects of rock and roll.

Writer Mat Snow, currently penning a new illustrated book on the Who, said Lambert’s self-implosion contributed to his being written out of the narrative. “The Who were never as big as the Beatles or Stones, nor, unlike Oldham or Napier-Bell, did Lambert write his memoirs,” he said. “Still, Townshend does not stint in stressing how important he was as an artistic and cultural mentor, and visionary for the group.”