Matthew Cain explores music’s extraordinary effect on the human brain, and learns that many composers are now exploiting the science of music in their work.

Travelling to the US, he meets Mike McReady, the creator of Hit Song Science - an algorithmic computer programme that shows how every hit song ever recorded falls into ‘hit clusters’, with many hits using the same four chords.

Now, artists and record labels are turning to the programme to predict chart success.

Using brain scans and monitors, Cain sees how listening to his favourite music changes his heartbeat and skin temperature and discovers clues to the evolutionary basis of music. He finds out how rhythm can bond people, and how different chords, tempo and rhythm stimulate the brain to release chemicals and produce certain moods.

Cain meets singer Will Young and composer Eg White to discuss if song writing is a creative process or a scientific one. Cain and White create a new tune specially crafted to tap into the reward pathways of the brain, and test it out at a nightclub. Will it be a hit on the dancefloor?

Can music be cynically created to move us? Or does it still need a mysterious musical brilliance and a cultural context to stand the test of time?