 Once Vig learned about the analog project, at first he considered Grohl was joking, but then replied that "You guys have to play really well, because nothing is gonna be fixed" since mistakes are not as easily correctable as in a digital recording. With that in mind, the band spent three weeks doing pre-production and rehearsals at Studio 606, where the composition was completed, going "from forty songs to fourteen", and said songs were rehearsed to be recorded live, while in previous records, as put by Mendel, "we 'd often come up with parts in the studio, and the songs would evolve". Smear added that the band committed to not change what would end recorded: " Whatever we did, we didn ’ t change it. If a distorted vocal went through a pedal, that ’ s what it was going to be. ”
