Standing by a piano, holding a teapot – and with an impish glint in his eye that is unmistakably reminiscent of Tony Bennett – the American composer Alvin Lucier is telling Viola Rusche and Hauke Harder, the producers of this documentary about his life and work and ideas, a story. ‘I once asked an architect how much it would cost to build a concert hall with a roof that could lift on and off,’ Lucier says, before pausing for comic effect with timing worthy of a stand-up. ‘Millions of dollars!’ comes the retort – as if, darn it, who would be silly enough not to design a concert hall with a peel-off roof allowing sound to radiate out into the surrounding environment.

I’ve always admired and enjoyed Lucier’s music very much, and seeing first hand what a loveable old gent he is, all whimsy, wit and wisdom, is very heartening. The teapot is trademark Lucier. In the second half of his piece Nothing is Real, a small speaker is placed inside a teapot to amplify fragments of The Beatles’ ‘Strawberry Fields forever’ which he has played on a piano and recorded. And depending on the carefully notated positioning of the teapot lid against the inside of the piano, melodies drift to the surface as the sound of the piano finds itself sucked up through the teapot. Elsewhere we see him using a birdcall toy, walking around a room and aiming to provoke frequency interference beats against a hanging microphone; the birdsong takes flight when the beats vibrate most strongly, and it’s as if Luicer is communing with the animals.

His totemic sound-art piece I am sitting in a room – Lucier sitting in a room recording his voice which is continually replayed into the room, thus revealing the resonant properties of that room – punctuates the film, and quickly it becomes clear how fundamentally Lucier has redefined what it is to be ‘a composer’. Electronics are his portal into capturing the nature of sound and he draws an analogy with the sound of a stream, which is expressively beautiful even if the stream is not trying to be ‘self-expressive’. He signs off by quoting the American poet William Carlos Williams: ‘Don’t ask me what I’m trying to say, ask me what I made’, which about sums it up – so I’ll leave it at that.