Death by Alice Cooper, and Destroyer by Kiss. Thirty Seconds to Mars contacted Ezrin because they felt that he had the ability to help them achieve their own vision and create a distinct sound; moreover, the band's members grew up listing to his work with Pink Floyd, Kiss and Alice Cooper. Brian Virtue, who had previously worked with Jane's Addiction, joined the band and Ezrin in producing the record. Thirty Seconds to Mars retreated to the isolation of Wyoming's countryside in 2001 to record the album, tentatively titled Welcome to the Universe. The band and Ezrin chose an empty warehouse lot on 15,000 acres, starting an intense period of preproduction focused on fifty songs. The isolation allowed the band to work at a different pace. Jared Leto said that while recording in Wyoming, "there was an interesting dichotomy, a kind of contradiction with the technology and the organic world that we were surrounded [...] It's something that I think ended up in the music". Ezrin helped the band to understand the importance of an album's structure and how to create a progression, rather than a simple series of singles. "We really wanted to create something that had depth," Leto explained. He described the process of working with Ezrin as tumultuous but also fulfilling, having its own dynamics. He also stated that Virtue was a key element in helping the band define their sound. Although bassist Matt Wachter was a band member at the time, the majority of the bass tracks were recorded by Jared Leto, with Wachter only being credited as a band member. The track "Fallen", originally titled "Jupiter", was the first to be produced for the album. Thirty Seconds to Mars initially thought to exclude the track from the record since they were not satisfied with it, but then they decided to rework the song because there were people who had strong feelings about it. The track features programming by Danny Lohner and background vocals by Maynard James Keenan. Several musicians, including Elijah Blue Allman, Renn Hawkey, as well as producers Ezrin and Virtue, contributed on selected tracks. Composition Style and influences The style of the album combined progressive metal and space rock with influences and elements from new wave and electronica, utilizing programming and synthesizers. According to Jared Leto, the band wanted to create "something that had cohesiveness and kind of an atmospheric musical story to it".