As the CBSO swaps Symphony Hall for shopping centres, tram loops and the Bullring, chief executive Emma Stenning tells Andrew Palmer why a great orchestra's real stage might be the platform at New Street.

There is a particular kind of chaos that only a symphony orchestra can cause in a shopping centre, and Birmingham has had rather a lot of practice at it lately. Ask Emma Stenning, chief executive of the City of Birmingham Symphony Orchestra, about the moment this July when a Bullring crowd doing their Saturday shop found themselves ambushed by eighty musicians playing Black Sabbath, and she doesn't reach for corporate language about "audience engagement." She reaches for the memory itself.

"There was a genuinely moving moment when the orchestra played Mama, I'm Coming Home," she tells me, "and literally the Bullring Shopping Centre was brought to a standstill and people were singing along." It happened on Birmingham's first Ozzy [Osbourne] Day, a year on from the death of the city's most beloved son, and it is exactly the sort of thing that makes CBSO in the City — the orchestra's now-annual week of turning up uninvited but entirely welcome across Birmingham — rather harder to categorise than a standard concert season.

Is it outreach? Marketing? Community theatre with better string sections? Stenning would say none of the above, and all of it at once. "What is the role of a contemporary orchestra in a city like Birmingham?" is the question she says the CBSO asks itself constantly, and this week is her answer in practice rather than in a mission statement: brass quintets outside Zara in Solihull's Touchwood centre, Jess Gillam leading a play-along that spans six-year-olds to eighty-nine-year-olds, and — should you find yourself on the number one tram between Edgbaston and Wolverhampton some quiet weekday morning — the possibly disorientating experience of your commute being soundtracked by one of the world's leading conductors on an electric keyboard.

That conductor is Kazuki Yamada, and by Stenning's account he treats CBSO in the City less as a duty and more as the best week of his professional year. "He genuinely spends the rest of the time running around the city," she says, of a man who by rights should be resting his baton arm between performances. "We all have these sort of slightly garish T-shirts that just say CBSO in massive letters on the front. His says 'Chief Conductor' on the back as well." It is hard to imagine the conductor of, say, the Berlin Philharmonic handing out flyers at the Botanical Gardens bandstand, which is rather the point.

That instinct for turning up where people already are has changed the orchestra from the inside as much as it has changed how Birmingham sees it. Stenning points to a collaboration last season with Fatt Butcher's LGBTQ choir, The Full Fatt Sound, with CBSO players joining in, as one of the moments that reshaped her thinking. "It was one of the most sort of radical and uplifting nights," she says, still audibly delighted by it. What she hopes the orchestra is becoming, she says, is "slightly more porous" — open to collaboration, open to the city, and stretched by both in ways that make it feel more rooted in Birmingham rather than less.

That porousness extends to some unlikely bedfellows. A string quartet playing among the pre-Raphaelite paintings at Birmingham Museum & Art Gallery is one thing; sharing a room with Joe Lycett ‘Mr Birmingham’s’ exhibition, in a venue currently home to his EVERY THING MUST GO show, is quite another, and this year's addition of a brass quintet outside Zara in Solihull's Touchwood centre suggests the orchestra has stopped worrying about dignity altogether. There is a method to it, Stenning insists — Solihull's marketing data apparently shows a high concentration of culturally engaged residents who simply aren't yet CBSO regulars, so a good noisy quintet by the shops becomes less stunt than strategy. Even Jess Gillam's mass play-along, which this year spans six-year-olds to eighty-nine-year-olds and reportedly involves something Gillam describes as "a rusty saxophone band," went through several rounds of debate over where in the city it should actually happen — Centenary Square and outside the council house were both floated — before the team settled on Brindley Place.

None of this happened by grand design, or not entirely. The whole enterprise traces back three years to a foreign tour that fell through and a gloomy moment for a city battered by council bankruptcy and bin strikes. "We were sat at the table going, well, what should we do with this week?" Stenning recalls. "That's when we just said, well, let's tour Birmingham instead. Let's be on tour in our home city." The phrase she uses for the underlying idea is disarmingly simple: before you can invite people in, "we have to have a gift." The orchestra, in other words, goes out looking for Birmingham rather than waiting politely for Birmingham to come and find it at Symphony Hall.

It works, on the evidence of the numbers as much as the anecdotes. Around 2,000 people took up last year's £1 golden ticket offer, three-quarters of them attending for the first time, and the orchestra now has a deliberate follow-up strategy — a Christmas offer, ongoing contact — designed to turn a novelty pound coin into a season ticket habit. There is a pleasing irony in an orchestra famous for precision timing not quite having cracked its own next big idea: Stenning still dreams of a floating stage on the canal basin, a project she admits "we haven't yet quite found the resources" for, which suggests even the CBSO occasionally has to busk it.

Word travels between orchestras faster than a well-rehearsed allegro. The Hallé's David Butcher apparently asked Stenning's permission, only half in jest, to borrow the idea for Manchester. Which raises the obvious question for readers rather further north than Birmingham: if a city can be serenaded into loving its own orchestra, why stop at one?

Leeds already has Opera North, an international piano competition to its name and a Town Hall with a fine musical pedigree of its own; the North East and Cumbria have community choirs, brass bands and cathedral organs deep in their civic bloodstream, all quietly proving Stenning's underlying point without anyone having called it a "strategy" yet. The raw material for a Yorkshire or Lancashire equivalent — a market square instead of a shopping mall, a Pennine bandstand instead of a canal basin — is arguably already there, waiting for someone with Kazuki Yamada's nerve to get on a tram with a keyboard.

Stenning's own route into classical music was via theatre rather than the conservatoire, which she credits for a certain clarity about what an orchestra is actually for. "One of the greatest opportunities for music is that it doesn't involve language, but it communicates," she says. "That has to be about access, as it is the root of everything." It is a neat thought to leave a shopping centre brass quintet with: no interval, no dress code, and no programme notes required — just an orchestra, deciding that the city is worth playing for whether or not the city bought a ticket.

DATE	TIMES	EVENT & LOCATION
Thursday 27 August	11:30am & 1:30pm	Notelets: Wind in the Willows at Birmingham Library
	11:30am	Solo Harp at Birmingham Children’s Hospital
Friday 28 August	3pm & 5pm	Full Orchestra at New Street Station
	2.30pm	Pianist John Reid performs on Angela de Cruz’s Upright Piano at Ikon Gallery, presented by BCMG
Saturday 29 August	10:30am	Flute & Harp duo at Birmingham Library
	11:30am	Kazuki Yamada on the CBSO Branded Tram
	2pm	CBSO Brass at Touchwood Solihull
	2:30pm	String Quartet at The Exchange
	2:45pm & 4pm	Saxophones in the City with Jess Gillam in Brindleyplace
Sunday 30 August	11am & 2pm	String Trio and String Quartet in Birmingham Museum & Art Gallery
	2pm & 6pm	Open for Business (Immersive Community Opera) across multiple sites in Digbeth (free but ticketed)
	2pm	CBSO Winds in Birmingham Botanical Gardens
Monday 31 August	1pm & 3pm	Full Orchestra in the Bullring
	2pm	Solo Harp at Birmingham Botanical Gardens

Full details of all CBSO in the City events at: cbso.co.uk/cbso-in-the-city