When the Commonwealth Games organisers announced their plans to demolish five of the six remaining blocks of Red Road Flats as part of the opening ceremony this summer, Red Note found themselves with an inadvertent marketing coup on their hands.

This week the Scottish contemporary music ensemble perform Elbow Room: a new work by composer Thomas Butler devised around ideas of urban destruction and regeneration in Glasgow. Butler had been gestating Elbow Room for years, but as he and his Red Note colleagues watched the online petition against the flats' demolition notch up 17,000 signatures and the Games organisers perform a begrudgingly conspicuous U-turn, the piece took on an eerie timeliness.

Elbow Room's starting point was in fact a pair of archive urban planning documentaries sponsored by Glasgow Corporation. Today they make for fascinating and disturbing viewing. The first, released in 1949, is a seven-minute piece called Glasgow Today and Tomorrow. It details a notorious city redevelopment plan devised during the dying embers of the Second World War, when the Corporation's chief engineer - a man grandiosely named Robert Bruce - was charged with addressing the city's chronic overcrowding and poverty.

"A city of congested buildings and narrow roads," clips the film's plumby, patronising voice-over. "A great population living under outmoded conditions which give rise to much confusion as well as discomfort. It is Glasgow: a city of contrasts, where beautiful districts alternate with congested and ill-planned areas..."

The implications of Bruce's redevelopment plan were staggering. With an ambition befitting his name, he proposed the complete destruction of central Victorian Glasgow and its replacement with a new "healthy and beautiful city" of modern concrete architecture. He proposed to flatten many of our proudest buildings: away with Central Station, Glasgow School of Art, Kelvingrove Art Gallery, the City Chambers. In their place would have come a sweep of new-built service industries and towering, futuristic housing blocks around the periphery. The plan was unveiled in March 1945 but rejected - at least in part. Elements of Bruce's designs filtered through into the road network that would form the M8 and the M74, and into housing projects such as Sam Bunton's Red Road Flats.

The second film behind Elbow Room is Glasgow 1980, made in 1971. Instead of a bright-eyed vision of the future, this is a snapshot of a city already undergoing seismic overhall. The film was edited by Bill Forsyth and it shows in the long sweeping shots panning across pristine motorway systems and the thrumming, lounge-pop soundtrack.

"If the roads are the bones of the city," says the breathless voice-over, now Glasgow-accented, "then the flesh is the housing developments around it." Glasgow 1980 was the first of what was intended to be a pair of films tracing the city's development in the 1970s, but filming for the sequel (due to be called Glasgow's Progress) was cancelled in 1978 because "there seemed to be no end to the urban renewal in sight". Plus ca change.

So how does all of this translate into a new piece of contemporary classical music? Elbow Room is scored for violin, cello, percussion, electric guitar, synthesizer, clarinet and bass clarinet. It contains three movements, the first two of which correspond to extracts from the two Corporation films. Butler draws his inspiration from the patronising voice-over, from the glitches and scratches on the films' ageing audio, from the 1970s synthesizer soundtrack. The final movement brings us up to date, containing field recordings taken from some of the locations that appear in the films. "In some ways it's all fantasy," Butler says. "Some of the city plans were inspired by the novels of JG Ballard, as if a utopian futuristic vision that was totally remote from the reality of actually living in these place. So I've taken what is real and made a musical fantasy out of it." The name, Elbow Room, comes from the 1949 film, which describes Glasgow of the future as offering more breathing space and more elbow room to its citizens.

This week's performances mark the culmination of an 18-month 'embedded composer-in-residence' scheme that has seen Butler working with Red Note in almost every conceivable capacity. The scheme is funded by the UK-wide new-music agency Sound and Music and teams up emerging composers with established ensembles. Usually the final outcome is a straight-forward commission, but Red Note wanted Butler to produce as well as write the music.

"They made the residency far more intensive than they needed to," says Butler. "I've been involved in everything from booking venues and coordinating texts to unloading percussion for the Red Note gig at Huddersfield Contemporary Music Festival and reattaching the spare wheel of Robert Irvine's Land Rover on Coll."

Which might sound like pure opportunism on the ensemble's part, but Butler explains that it's more than that. "Their idea was to underline that in today's music industry there is no point sitting around waiting for the phone to ring. As a composer you need to be able to make things happen. Red Note have given me a very warts-and-all view of the industry, and it has already an impact on how I approach composition.

"Elbow Room, for example, started with nothing but a piece of paper with a budget written on it. When you know how much it costs to use loads of percussion or extra woodwinds or complex electronics, then you start to appreciate the attraction of pared-down orchestration." He pauses. "Actually, maybe every composer should have to work as a producer for at least a day. It would solve a lot of problems down the line."

Red Note perform Elbow Room at Summerhall, Edinburgh, tonight and The Arches, Glasgow, tomorrow.