The rocker was joined by thirty members of The Liberty Choir on the single, and seven of them once served time in Wandsworth Prison in London, where Gilmour's adopted son Charlie spent four months for his role in a protest against university tuition fees in 2010.

His son's experience in prison made him aware of the rehabilitation choir project, which Gilmour and his wife Polly Samson financially support, and he wants to raise awareness so it can expand to other prisons.

Gilmour tells BBC News, "Charlie's experience was something that has impacted on us and has made us more aware of the prison system and what could and should be done to improve it... We're just helping out by being part of this initiative, which will hopefully spread."

Rattle That Lock is from Gilmour's upcoming solo album of the same name, which is set for release on 18 September (15).