Recorded sporadically over five years from 2015 to 2019, Sixty Summers was shaped profoundly by Stone's key collaborators on the album: Thomas Bartlett, aka Doveman, and Annie Clark, the Grammy-winning singer, songwriter and producer known as St. Vincent. Bartlett and Clark were the symbiotic pair Stone needed to realise her first pop vision. A wizard of production and songwriting, Bartlett helped coax Sixty Summers' independent, elemental spirit from Stone, writing and recording over 50 demos with her at his studio in New York.