Conductor Charles Hazlewood and Dr Brian May of Queen celebrate the Doppler effect.
The Doppler effect not only proved that the universe was expanding, it also helped John Lennon sound like the Dalai Lama on a mountaintop - or so he hoped.
BBC Radio 4 turns the volume up to 11, as conductor Charles Hazlewood recreates an ambitious experiment which first proved the Doppler Effect in 1845, while Dr Brian May, guitarist with rock band Queen gives him the low-down on the Doppler Shift in astrophysics.
A steam train, a brass band and an internationally famous conductor recreate one of the most unusual experiments - to prove the existence of the Doppler Effect - what could possibly go wrong?
So what is the Doppler Effect? Everyone today is aware of it, even if they can't name it. The pitch of the siren on a passing police car appears to change as it zooms past - the note appearing to rise and fall as the source of the sound approaches and fades away.
Austrian physicist Christian Doppler, who first proposed his theory in 1842, was interested in the behaviour of light waves, but because sound waves are similar - if longer - the way the theory was tested was using a steam train loaded up with trumpet players holding a single note, travelling at speed past a station.
With the help of the locomotive steam power of the Great Central Railway and the wind power of the Hathern Brass Band, Charles fills a railway carriage with brass players and sends them from Loughborough, through Quorn Station, blasting out a single note, to recreate that moment.
Gavin Pretor-Pinney, author of "The Wave Watcher's Companion" helps Hazelwood get to grips with the physics and pit falls behind the original experiment.
Producer: Sara Jane Hall
Choir: Siona Stockel, Naomi MacLeod-Jones, Stephen Harvey, Tim Wilson, Iain MacLeod-Jones, Oscar Golden-Lee, Craig Bissex, William Drakett.
Music in the programme: