So: "welcoming and accessible" for whom? It's hard to think of anything better calculated to confirm classical concert-going's image as a moribund museum than to lock the whole experience away beneath a giant glass display case.
But maybe the SBC is just being realistic. After all, while pop has always been an intrinsically urban animal, classical music has long turned a deaf ear to its metropolitan surroundings in pursuit of some pastoral ideal. And even when classical composers have overcome their fear and loathing of the city, they have rarely chosen to expose the sweaty underbelly of civic society. Take Elgar's Cockaigne, premiered in the first year of this century. The overture may be subtitled "In London Town", yet its punning title - a play on the mythic land of lost content - betrays its the-sun-shall-never-set perspective on the imperial capital. Yes, we may be able to detect the tambourine-jangling of a passing Sally Army band towards the close, yet you'd listen in vain for a hint of the shabby sinners at the soup kitchen door.
Or take Vaughan Williams's A London Symphony. Though the composer repeatedly denied that the work was in any detailed sense descriptive (and bar the opening and closing chimes of Big Ben it's impossible to guess the symphony's supposed civic subject), the images he allowed were of the rolling majesty of the River Thames, of happy holiday-makers out on Hampstead Heath, of smart society enjoying a night out on the town or of the peace and quiet of a bygone Bloomsbury square. Though premiered on the eve of the Great War, Vaughan Williams's London is located firmly in Edwardian fairyland.
And for every London Symphony that Vaughan Williams ventured, he ploughed a half-dozen pastoral furrows, whether in On Wenlock Edge or A Norfolk Rhapsody or The Lark Ascending. Yet Williams was but the flower of a whole crop of 20th-century British composers whose incurable rurality earned them the nickname, "the Cowpat School".
Not that cityphobia is exclusively an English disease. Until recently, few composers anywhere have engaged with urban experience. Is it simply that classical music's historical reliance on natural means of production - wood, gut, skin, reed, quill - has given it an inherent antipathy to the city?
Now, a quick flip through the classical catalogue might seem to contradict this. Didn't Mozart compose three city symphonies: one Linz, one Prague and one Paris? While Papa Haydn left no less than six Paris Symphonies, and half a dozen London ones, too. Yet anyone trying to use Haydn's Symphony No 104 as a musical A-Z of 18th-century London would be lost. When it comes to Haydn and Mozart, such toponymic sobriquets denote nothing more than the place of first performance or the source of the composer's commission; in Haydn's case an aristocratic backer of a Parisian masonic music society and a German immigrant violinist turned London concert promoter respectively.
Perhaps cities might have done more to raise their own musical profiles if they had actually commissioned a few celebratory pieces for themselves. But apart from an almost never performed Moscow cantata by Tchaikovsky, commissioned to mark the city's 800th anniversary, and the curious Fte des Belles Eaux, for six electronically ululating Ondes Martenot, which Olivier Messiaen composed to accompany a Seine-side fireworks display during the 1937 Paris Exhibition, precious few examples of enlightened civic commissioning survive from the past.
Practically the only example this country has to offer - apart from Paul McCartney's Liverpool Oratorio (and only a rocker on the make would think to use a long-obsolete classical form to pay tribute to so vibrant a musical city) - was in 1992 when the Milton Keynes Development Corporation (misguidedly ditching the Michael Nyman number it was then using on its television ads) held an open competition for a new orchestral work to celebrate its silver jubilee. But then, as the winner Ian Hughes observed, Milton Keynes is itself "a bit of a contradiction - a city in the countryside". His winning score, Panorama (like most occasional pieces, only ever heard very occasionally thereafter), chose to play up the city's attractions as "a green oasis".
But that's a typical ruse even among the few composers who have made a name for themselves scoring cityscapes. Ottorino Respighi, for example, dispatched three whole suites of musical picture postcards from Rome. Yet, in both The Fountains and The Pines of Rome, the composer skirts the throbbing metropolitan heart of the Eternal City to dally in those few quiet corners of displaced countryside that even the most redeveloped cities have left bare of concrete; while, in his Roman Festivals, Respighi (like Berlioz in his own Roman Carnival overture or Wagner in his Mastersingers of Nuremberg) chose to depict the city when it is least like itself, when it is en fte.
It is understandable. Where, even today, classical music retains an ethos of order, structure, beauty, or if not beauty, at least proportion, the city, particularly in its late 20th-century manifestation, presents only an image of chaos, confusion, brutality and, above all, noise. And while classical music has a well-developed metaphorical language for conveying the wonders of nature - the babbling brook, the wind in the trees, the coming of spring - it has not until now found a happy way of transforming the sounds of the city.
Gershwin, of course, set an example, with all those honking Twenties taxi horns in An American in Paris. But Puccini got there some 10 years earlier in his Seine-set, one-act Il Tabarro, which includes the real- life noises not only of distant car hooters and tug-boat whistles but of a song-seller's out-of-tune organ grinding out the melody of Mimi's aria from his earlier (1896) Paris opera, La Bohme. It was Puccini, too, who, when writing Tosca, scaled the citadel of Castel Sant' Angelo early one morning to annotate the exact volume and pitch of the countless church bells that awaken Rome each dawn in order to reproduce the effect in his Act Three prelude.
Of course, it has been the Americans who have set the pace. Charles Ives perhaps began it all with Central Park in the Dark, a short, eight- minute nocturne from 1906 in which the strains of a distant Dixieland jazz band and a passing big parade can be briefly heard. Despite being "big in the city", however, Ives was undoubtedly happier, as a composer, recapturing the memory of New England Holidays. The essential nostalgia of his New York score is betrayed by the customary abbreviation of its full title, Central Park in the Dark in the Good Old Summertime.
What one might see as the existential angst of the city dweller is perhaps better captured in that work's companion piece, The Unanswered Question - a five-minute dialogue (originally subtitled "A Cosmic Landscape") between a solo trumpet, repeatedly posing the "perennial question of existence", and an increasingly frantic flute quartet, attempting (vainly) to give the answer, against an aural backdrop of off-stage strings. And it is surely an echo of this Ivesian angst - the lone voice sighing out into the night - that one can hear in the querulous solo trumpet of Aaron Copland's later cityscape Quiet City.
It is odd that Copland, better known for his cowboy ballets Billy the Kid, Rodeo and the Shaker-inspired Appalachian Spring, should have created two of the strongest city scores. Like Philip Glass's heart-racing soundtrack to the time-lapse movie Koyaanisqatsi - perhaps the ultimate musical pace-setter to the rush of America's streets (but hardly, or rather minimally, classical) - both Quiet City and Music for a Great City began as sonic responses to visual scenarios, the first as incidental music to a 1939 Irwin Shaw play about "all the lonely people", the second as soundtrack to a 1961 Jack Garfine movie, Something Wild, about a young girl raped and abducted from a city park. Copland's jazzy score mirrors Garfine's brand of documentary realism (the film was shot in New York), with its crashing dissonances and pounding chords, and the city's coldly seductive allure, the glint of steel and glass.
Copland's protg, Leonard Bernstein, bit deepest into the Big Apple in a succession of city-set pieces from Trouble in Tahiti (actually about marital breakdown in the 'Burbs), through Fancy Free, On the Town and Wonderful Town, to West Side Story and beyond. Yet, like Kurt Weill - one of the few European composers unafraid to tackle the seamy side of 20th-century city life in scores such as The Threepenny Opera, The Rise and Fall of Mahagonny and The Seven Deadly Sins - Bernstein merely proves the rule that the more streetwise composers want to sound, the less "classical" they have to be.
Pop culture rules, and British composers as diverse as Sir Michael Tippett, Mark-Anthony Turnage and Sir Harrison Birtwistle have had to invoke the wail of saxes to summon up their nightmare visions of the city in their recent operas New Year, Greek and The Second Mrs Kong.
Thanks to digital sampling, though, today's composers now have a much more direct way of turning a city's sounds into music. Where George Gershwin once had to buy up real French taxi horns and carry them back to New York for the premiere of An American in Paris, he could now just step out into a busy Paris boulevard, point his trusty DAT at the nearest cab and then fly back to his downtown studio to manipulate the recording, before re-integrating it with live performers through the wonders of MIDI technology.
And that is just what New York composer Steve Reich has done in his new score City Life, coming to a city near you next month on an Arts Council Contemporary Music Network tour. A sonic farewell to the city where Reich has spent his life, and from which he is now determined to escape, City Life includes not only the sampled sounds of car horns, but, in its second and fourth movements, the hammering of a pile-driver combined with the beating of a human heart, or, in the central movement, the rhythmic chanting of demonstrators recorded outside City Hall, just across the street from where Reich lives.
So it is a touch ironic that the CMN tour should be starting off on Wednesday at the South Bank Centre - one last chance to let the noise of the city into the concert halls before the soundproof glass comes down.