Crucial is the fifth track on the second disc of Prince’s 20th album Crystal Ball (his fourth using the name ). The album is not clearly divided between Prince tracks and tracks, but the liner notes' discussion of this track state “All instruments and vocals by Prince”. The original lyrics version (with the later Clare Fischer arrangement) was released as the tenth track of Vault Tracks part 2, one of the discs with previously unreleased tracks included with the Sign O’ The Times Super Deluxe Edition in September 2020.
Basic tracking took place on 13 September 1986 at Prince’s Galpin Blvd Home Studio in Chanhassen, Minnesota (four days after the end of the Parade Tour in Japan, the day before recording The Cocoa Boys). Two days later Prince worked further on the song recording almost completely new lyrics for it.
Eric Leeds added a saxophone part on 8 November 1986, at Sunset Sound in Hollywood, California, at Prince’s request, but when Prince heard it, he let Leeds know that the main saxophone solo was in place of the guitar solo, so the saxophone solo was discarded. Leeds then recorded a different sax part the next day.
The song was written specifically for the planned musical The Dawn, which was ultimately abandoned, and the song was never intended for any of Prince’s many late-1986 album projects (although the album notes in Crystal Ball state that it was intended for Sign O’ The Times and was replaced by Adore). The title is mentioned in an early 1987 draft of what would become Graffiti Bridge.
It is believed that the version used for release on Crystal Ball was edited in 1997, although this has not been confirmed.