Metallica spent two months writing the songs for The Black Album in mid-1990.
James Hetfield and Lars Ulrich were the main songwriting partnership, with Hetfield handling the lyrics. They frequently worked together at Ulrich's house in Berkeley, California. Kirk Hammett and Jason Newsted also contributed ideas, riffs, and concepts to the material.
The writing period was much shorter than the complete production process. Recording began in October 1990 and continued into June 1991, while the band spent many months refining performances, recording takes, overdubbing, and mixing. That difference explains why the album is sometimes described as taking nearly a year to make even though the core songs were written in two months.
Some ideas originated during the Damaged Justice Tour, before the formal mid-1990 writing period. “Enter Sandman,” “The Unforgiven,” “Nothing Else Matters,” and “Wherever I May Roam” were among the early demos recorded in August 1990.