All eleven of the songs on Crack-Up were written by Robin Pecknold. The album was co-produced by Pecknold and Skyler Skjelset, his longtime bandmate, collaborator, and childhood friend. Crack-Up was recorded at various locations across the United States between July 2016 and January 2017: at Electric Lady Studios, Sear Sound, The Void, Rare Book Room, Avast, and The Unknown. Phil Ek mixed the album, at Sear Sound, and it was mastered by Greg Calbi at Sterling Sound. Fleet Foxes is Robin Pecknold (vocals, multi-instrumentalist), Skyler Skjelset (multi-instrumentalist, vocals), Casey Wescott (multi-instrumentalist, vocals), Christian Wargo (multi-instrumentalist, vocals), and Morgan Henderson (multi-instrumentalist).