As New England rural idyll gives way to polluted, disease-ridden urban city life, with fumes and traffic everywhere, Aaron Copland’s score for The City is wonderfully evocative of the images portrayed on the big screen. When first seen, it wasn’t just the screen that was huge. An audience of tens of thousands of people would have experienced Lewis Mumford’s documentary film, commissioned for New York’s 1939 World Fair, and Copland’s accompanying music.

Performing the Copland score alongside a showing of the film, Auricle Ensemble are letting modern audiences hear the music live for the first time outside the USA. ‘You expect all of his music to be done by everyone,’ says music director Chris Swaffer. ‘The publishers have really helped us to be certain that it hasn’t been performed elsewhere before us.’ The downside of finding a rarely performed gem like this is that the instrumental parts are not exactly in pristine condition. ‘It was quite hard to access the parts,’ says Swaffer, ‘which were in the state they were left in when the film was first made, and we needed special permission to get hold of them. They took some reassembling.’ Now, however, the parts are restored and ready for other groups to perform.

‘It’s great music,’ says Swaffer, ‘classic Copland, with open harmonies, folk tunes, then busy jazz in the New York scenes with pastiche and Shostakovich tucked away in there too. There are some fantastic moments.’ Scored for 20 instrumentalists, it underpins a film of social realism, inspired by the Scottish pioneering town planner, Patrick Geddes. ‘It’s sometimes a little bit uncomfortable,’ says Swaffer, ‘but still very relevant today.’ Performed alongside Copland’s Quiet City, in its original four-piece version, plus special commission Sprawl, by Steve Forman, it’s a night of urban planning with a difference.

Summerhall, Edinburgh, Mon 28 Jan; Old Fruitmarket, Glasgow, Sun 17 Feb (part of Glasgow Music & Film Festival).