Metallica's 1991 album, known as The Black Album, is commonly reported to have cost about US$1 million to produce.
The high cost reflected an unusually demanding recording process. Sessions took place mainly at One on One Recording Studios in Los Angeles, with additional work at Little Mountain Sound Studios in Vancouver and A&M Studios in Hollywood. Recording lasted roughly eight months.
Producer Bob Rock pushed the band to perform more collaboratively and to record as many takes as necessary. The musicians were known for perfectionism, and the production team selected and edited performances into finished tracks. The album was also remixed three times before completion.
The reported figure is an estimate rather than a precise itemized public budget. It is often repeated alongside accounts of the tense sessions and the personal strain experienced by several band members. The investment ultimately paid off when the album became a global commercial landmark.