“Enter Sandman” was written first for Metallica's 1991 album, even though it received its lyrics last.
The song developed from a guitar riff by Kirk Hammett, who had been influenced by Soundgarden's 1989 album Louder Than Love. Lars Ulrich reshaped the riff's repetition, and the instrumental framework came together quickly.
James Hetfield took longer to settle on the vocal melody and words. The finished lyrics deal with childhood nightmares and include bedtime-prayer imagery, giving the song a darker meaning than its catchy, accessible musical surface initially suggests.
This timeline is easy to misremember because “Enter Sandman” was also the first single and the album's opening track. It was not simply written late to match the single campaign; it was the first album song the band had written. The completed song was mixed first as well, because its sound established the production direction for the rest of the record.