B ristol needs to take risks. There is little doubt in my mind that Manchester has made itself into Britain's funkiest metropolitan city, but could polite southern Bristol now outdo our funky northern friends?

While we are the home of the 'Bristol Sound' – Massive Attack, Portishead and others, I think this has been treated as an exception in an otherwise relatively staid city.

Where was our Tony Wilson, 'Mr Manchester', the exceptional music producer behind the city's famous Hacienda?

Where was our Sex Pistols concert that changed popular music in the mid 70s? Where was our 'can do' attitude that attracted all this alternative culture?

Suddenly sleepy old Bristol is now, where it should be, high on the list of funky cities, and it seems it is all down to one anarchic, witty and mysterious character who scribbles rather well on walls, even if the rest of the world previously thought Banksy belonged to London or even to New York.

Some say Banksy has sold out with his show in the City Museum and Art Gallery, but that is to misunderstand his obsession with the element of surprise.

Surely the expected thing, when it was (faintly) rumoured that he was to do something big in Bristol, was that it would be 'out of the system', probably illegal, but certainly not by secretive arrangement with the city itself.

How could the city council possibly keep such a secret? It could have been an almighty spoof played on city officers, but Kate Brindley, the museum director, took it on herself to go with Banksy's offer.

Are there many art gallery directors that would have taken the risk?

This to me is the big story.

Risk-taking is simply not in the DNA of the public servant, and to take a big decision without reference to your political bosses is anathema, and yet she did it.

Kate and her small band of confidantes deserve huge thanks from Bristol.

Where would she be if it had all gone sour in some way – banished to some obscure arts institute in the north to keep her out of harm's way?

The thing that did seem to pass the world by is the extraordinary build-up to the Banksy exhibition.

The second Urban Paint Festival, UPFEST, attracted 140 national and international urban artists to a weekend of phenomenal creativity and the RWA opened its doors to 50 Bristol 'graffiti' artists to do their own thing on the revered walls, for what was really a more radical show than Banksy's.

Who would have thought it – the RWA and the City Museum go funky – where does that leave Arnolfini? Has the 'radical' Arnolfini Gallery, of which I am proud to be a Trustee, become the establishment, and the establishment become the radical?

Are we turning Bristol culture on its head?

I suggest this is a cue to other areas of culture in Bristol, that we should not play safe but play with our imagination, or we shall always get what we always got.

Let's shout from the rooftops and across the world's webs that Bristol is a music capital and make sure we do all we can to inspire new talent.

Let's not give up on the concept of an arena that matches Manchester, but maybe think up new forms and use our public property with more imagination.

Let's shout from the rooftops that we are supreme in wildlife filming, animation and circus school – and in times of public and private stringency, let's work with the most daring entrepreneurs to make things happen. In short, let's take risks.