Terry Jones, who has died aged 77, was perhaps not the most recognised member of Monty Python. In a group of such strong performers, where sketches were cast based on who had been funniest in the readthrough, he was the one most often cast as sidekicks and straight men. Yet creatively he was utterly indispensable – arguably the group’s most essential member.

The team behind Monty Python’s Flying Circus was put together by John Cleese, who wanted to do a new TV show with a group dynamic. There’s no doubt it wouldn’t have happened without Cleese: he was the best-known member of the group and fronted the proposal to the BBC, who were keen to find a vehicle for him. Yet as the members discussed what form the show would take, it was Jones who emerged with the most ambitious vision.

In March 1969, Jones watched Spike Milligan’s new sketch show Q5, co-written by Milligan and Neil Shand, and was both thrilled and dismayed. Jones wanted Python to feel fresh and push the envelope, but Q5 had beaten them to it. As well as being surreal, satirical and sometimes tasteless, Q5 acknowledged the mechanics of television, showing the edges of the set and having the actors drop out of character mid-sketch. Moreover, the sketches often dispensed with traditional structure. “I suddenly realised we’d all been writing clichés in a way,” said Jones, “a three-minute sketch which had a beginning, middle and end, with a punchline.”

Jones immediately phoned Cleese, who agreed that Q5 was what he’d wanted Python to be. Rallying themselves, they agreed that Milligan and Shand had merely upped the ante, and they had to take his approach further. But while Cleese and his writing partner Graham Chapman mainly saw the freeform approach of Q5 as a way of liberating themselves from formal constraints (a comedy writer will take any excuse to get out of writing punchlines), Jones saw an opportunity to do something bigger.

Jones, Michael Palin and Eric Idle had been drafted into Python principally because Cleese and Chapman loved their work on Do Not Adjust Your Set. Everyone agreed that another of their colleagues, the American animator Terry Gilliam, should be involved somehow. Jones saw a stream-of-consciousness animation Gilliam had made for DNAYS called “Beware of Elephants” and realised that approach could be applied to a whole show. Whereas Q5 had simply stopped sketches when there was no punchline, Jones conceived sketches that flowed together, using connected characters, settings, ideas, meta gags – whatever worked. If two sketches needed a weirder cognitive leap to join them up, Gilliam would connect them with animation.

This is Python. Yes, people remember dozens of individual sketches, and can recite them for you. But if you ask them what made Python different and new, most people will talk about sketches running into each other. It was a brilliant format to combine surrealism and satire: it was dreamlike, your brain jumbling the familiar and the strange as it tries to make sense of things.

And it was Terry Jones’ idea. Indeed, without that conceptual framework it might not have worked at all – achieving creative cohesion between six men all writing deliberately weird material is no mean feat.

Jones saw Python in a bigger, more interconnected way, which is why he went on to direct the films, first with Gilliam and then on his own. The Holy Grail and Life of Brian are the team’s most celebrated achievements, and they were rooted in Jones’ concept of doing something more than isolated sketches. “He was the beating heart of it all,” says comedy writer Ian Martin, who was in the studio audience when The Bishop sketch was recorded. When Jones did get centre stage as a performer, he was joyfully uninhibited: the Bishop’s crook fell apart when Jones dramatically slammed it on a desk. “Comedy literally smashing itself to bits and rebuilding into something NEW,” says Martin. “With gaffer tape, I think.”

Though every member of Python made a huge contribution to its success, you could conceivably take one out of the equation and it would’ve still been Python – lesser, but still recognisably Python. But not Terry Jones. He was essential.

Eddie Robson’s work includes the Radio 4 comedy Welcome To Our Village, Please Invade Carefully.