Jonny Greenwood on BBC Radio 4

Jonny Greenwood talks to the BBC at the Proms on the night of Horror Vacui, his piece for the violinist Daniel Pioro and 68 strings. He starts from Penderecki, who learned filters and white noise generation as a student in the 60s, then turned his back on them and made white noise with 48 strings. Greenwood took the idea to more recent electronics, artificial reverbs and delays.

The first part copies the palm speaker of the ondes Martenot, a wooden box with 24 strings across it that resonate with whatever note is played; Thom Yorke sings through it on “You and Whose Army?”. Here the orchestra becomes the resonant box around Pioro, and later it imitates digital echoes. It is not meant to sound like electronics. It is meant to be better, he says, admitting there is no modest way to put that, because human players can never be perfectly even across every frequency the way software is.

The Proms Youth Ensemble make up the numbers, and Pioro says he finally understands his dad's line about being around young people. In every tea break, Greenwood noticed, the mentors from the BBC National Orchestra of Wales took the young players aside to go over the ideas.