Omar Rodríguez-López – guitars, synthesizers, field recordings, production
Cedric Bixler-Zavala – vocals
Jon Theodore – drums
Isaiah "Ikey" Owens – keyboards
Juan Alderete de la Peña – bass
Marcel Rodriguez-Lopez – percussion, keyboards
Lenny Castro – additional percussion (all tracks)
Flea – trumpet on "The Widow" and "Miranda That Ghost Just Isn't Holy Anymore"
John Frusciante – first two guitar solos on "L'Via L'Viaquez"
Larry Harlow – piano on "L' Via L' Viaquez", treated clavinet on "Cassandra Gemini"
Adrián Terrazas-González – tenor sax, flute on "Cassandra Gemini"
Salvador (Chava) Hernandez – trumpet
Wayne Bergeron – trumpet
Randy Jones – tuba
Roger Manning – piano
Nicholas Lane – trombone
William Reichenbach – bass trombone
David Campbell – string, brass, piano, and percussion arrangements
Larry Corbett – cello
Suzie Katayama – cello
Violins:
Fernano Moreno
Erick Hernandez
Diego Casillas
Ernesto Molina
Joel Derouin
Roberto Cani
Mario De Leon
Peter Kent
Josefina Vergara