The title track, "Rattle That Lock", is available now to download and stream worldwide. The song begins with the four notes, created by Michaël Boumendil, which precede announcements at French SNCF railway stations which David Gilmour recorded on his iPhone at Aix-en-Provence station. Polly Samson's lyrics are inspired by Book II of John Milton's Paradise Lost, which features in her recent acclaimed novel, The Kindness. The single also features The Liberty Choir and singers Mica Paris and Louise Marshall.