Production and musical style
Countdown to Extinction is Megadeth's fifth studio album, and the second to feature the line-up of Dave Mustaine, Marty Friedman, David Ellefson and Nick Menza. In an interview for Billboard at the time, Mustaine admitted that he fired past members Chuck Behler and Jeff Young because they resisted his pleas to seek rehabilitative counseling. He added that it was a "major accomplishment" that all four members of Megadeth contributed material to the album, unlike their earlier releases which were "nearly all Mustaine". Mustaine also revealed that producer Max Norman had significant input to the album by making "a lot of suggestions and a lot of great artistic ideas". Guitarist Marty Friedman said that unlike Rust in Peace, the creation of this record was "completely different". He further stated that the band had changed the songs "a million times" before recording them on demo and entering the studio.
The music for Countdown to Extinction was written in two different sessions. The first session was done following the conclusion of Clash of the Titans tour, while the second session took place after a one-month break, in the fall of 1991. The album was recorded in the first half of 1992, when the Rodney King Riots took place. These events negatively affected the recording process, as the band was forced to leave the studio every night at six o'clock because of the enacted curfew. Dave Mustaine shared his experience: "There’s nothing worse than getting a creative moment and you have to leave. It was like a school bell ringing." The record was produced by Mustaine and Max Norman at The Enterprise in Burbank, California, while the mixing was handed by Norman with the help of Fred Kelly. Referring to the recording process, Mustaine said that Countdown to Extinction "was one of those records where everything was firing on all 12 cylinders and you just know it". He also said that it didn't take the band a long time to record the album because "records were a lot easier to make back then because the pressure wasn't quite as hard".
We'd take a break and go outside with a basketball and shoot some hoops and walk back in, and Dave would pick his guitar up, and out fell the riff to "Sweating Bullets".
— David Ellefson, on composing the music
Following Metallica's mainstream breakthrough in 1991, Mustaine stripped down Megadeth's sound, though the music remained as technically perfectionist as their previous releases. Drummer Nick Menza explained: "Metallica has definitely opened the doors for other bands to step through. We're obviously the next band to step through that doorway." Musically, Countdown to Extinction saw Megadeth beginning to incorporate more melody and mid-tempos into its traditional sound. Bassist David Ellefson noted that the band's goal was to "create music that had more of a groove to it," capitalizing on the melodic playing style employed by Friedman, and further assisted by the input of producer Norman. Author Thomas Harrison wrote that with this album, Megadeth's music became "more virtuosic than noisy and took the next step towards widespread acceptance".