"For the next hour, I need your ears". It's 1974 and someone is trying to recruit you for a listening experiment on public radio in Canada.

Pioneering Canadian composer and soundscape maestro, R Murray Schafer really wants you to commit: "if you're just listening to this programme casually, you'd better turn it off right now".

This audio experiment was part of a series on the CBC - the Canadian Broadcasting Company, called Soundscapes of Canada, consisting of ten hours of soundscape montage, field recordings and lessons in listening. From Church bells, to birdsong, to car horns and an entire episode made up of people across Canada giving the sound recordist directions: this was 'slow radio' years ahead of its time.

The series was recorded and produced by The World Soundscape Project, a group Schafer set up to raise the importance of the soundscape in what he saw as a world of increasing noise, which had reached "an apex of vulgarity". The group went on to publish Soundscape: The Tuning of the World - a vast anthology documenting just about every kind of sound you could imagine - natural, human-made and technological.

R Murray Schafer was many things – Canada’s preeminent experimental composer of the 20th Century, an artist, novelist, educator, musicologist, historian, and environmental activist. Schafer was also a romantic, with a strong sense of Canadian identity, who preferred rural life with an uncluttered sense of place. Critics, and he had many, accused him of being abrasive, a luddite, and prone to cultural appropriation.

Above all though, Murray was a passionate listener, constantly pushing his message of an "ecologically balanced soundscape" by asking "which sounds do we want to preserve, encourage, multiply?" In this sound-rich documentary (best enjoyed with headphones) John Drever, Professor of Acoustic Ecology and Sound Art at Goldsmiths, University of London explores Schafer’s life and legacy, as the soundscape now has an ISO framework for consideration in urban design and planning in the UK and beyond.

Contributors: Hildegard Westerkamp, Barry Truax, Ellen Waterman, Claude Schryer, Lisa Lavia, Tin Oberman, Andrew Mitchell and Francesco Aletta.

Use of 'Crescendo' courtesy of Martyn Ware

Presented by John Drever