There is a laminated card in a museum vitrine at the Bronx Museum of the Arts. It is a bicycle messenger licence, issued to Leonard McGurr by Elite Couriers, New York City. Beside it: a worn messenger bag and a few photographs of its owner on a track bike, in traffic, getting on with it. These are not the objects you expect to find in a mid-career retrospective. They are, arguably, the most interesting things in it.

McGurr came up on the subway system. West 103rd and Broadway, early 1970s, a fifteen-year-old who looked at the writing on the walls and on the city’s trains and understood immediately that they were an invitation. He adopted the name Futura 2000 - drawn from Kubrick, from the promise of something not yet arrived - and began painting. What distinguished him early was his departure from the letter-based tradition that defined the scene. He painted abstractions: fields of colour and form that had more to do with the surface of a canvas than the conventions of a tag. In 1980, he painted the first abstract wholecar. Martha Cooper photographed it. The car was called Break.

Futura, Break, 1980. Photograph: Martha Cooper

By the early 1980s he was showing at Patti Astor’s Fun Gallery alongside Basquiat, Haring, Rammellzee, Kenny Scharf. He recorded a rap track with The Clash. He was, by any measure, present at the beginning of something significant. Then the art market moved on from street art, as art markets do, and McGurr found himself on the wrong side of the fashion. He didn’t adjust his work to suit the moment. He picked up a messenger bag instead.

For the better part of a decade he rode a fixie across Manhattan for Elite Couriers. He also put in time at a post office in Queens. Neither fact is offered here as tragedy. The city was still his territory; the work was simply different. There is a particular kind of integrity in that refusal to become something else, to let the market re-educate you into a more convenient version of yourself. McGurr, by his own account, was not holding out. He was just living.

In 1992, he turned up in Berlin. The occasion was the first Cycle Messenger World Championships - a gathering of the global messenger community, self-organised, entirely without precedent. McGurr attended as a civilian; four years, he said, removed from active duty as a New York City fixie messenger. He brought company: his friends Stash and Gerb, and a box of cycling jerseys produced under a loose collective called GFS. The jerseys were for sale. It was a reasonable hustle.

Futura, DJ Shadow, James Lavelle. Circa 1995. Photographer unknown

At the same event, he met the people from Mo’ Wax Records. The London label -James Lavelle’s project, which would go on to release DJ Shadow’s Endtroducing and anchor a particular strain of mid-nineties cool - purchased his work and commissioned him for album artwork. The messenger championships that had seemed like a postscript turned out to be the opening of the next chapter. The fixie had delivered him somewhere.

What followed is more familiar: collaborations with Supreme and Nike, artwork for UNKLE, the Futura Laboratories line out of Fukuoka, the long-overdue museum retrospective at the Bronx in 2024. A return, of a kind, to the borough where his subway cars used to run. The laminated card in the vitrine is not included as a curiosity. It is there because the messenger years were not an interruption in the career of an artist. They were part of the shape of it.

Pointman artwork for Mo' Wax Records

McGurr is seventy now. Still in Brooklyn. Still on his bike. He has said, in recent years, that he is trying to be Lenny more than Futura - a distinction that only becomes available once you have stopped needing to make the other one. His Elite Couriers licence is in a museum. The city is still his territory.

Some careers are built. Some are simply lived, and the shape only becomes clear later, when you set it all out on a white wall and look.