Dan Parry helped with the album 21 as an assistant and vocal engineer. He worked on four tracks. Two, "I'll Be Waiting" and "Rolling in the Deep," were worked on by Paul Epworth (producer), Tom Elmhirst (mixer) and Mark Rankin (engineer). Another track, "Rumour Has It," was worked on by Elmhirst, Ryan Tedder (co-writer, producer, engineer) and Parry (assistant). The album's second single and final track, "Someone Like You," was worked on by Parry (asssistant), Elmhirst (mixer), and Philip Allen (engineer). It was produced by Dan Wilson and Adele.
Dan Parry worked on all the same tracks as Tom Elmhirst on the album.