Brion completed the Circles
album following Miller's death in September 2018. The producer recalled to The New York Times
how devastated he felt when he first listened back to the song during a flight.
"When I heard 'Once A Day' on that plane, it was like a knife in the heart," he said.
Brion added that Miller was "clearly trying to sort through his demons and was just being very, very honest, not trying to hide any of it."