A Perfect Circle has released four studio albums, the first three releasing in the early 2000s: Mer de Noms, their debut album in 2000, and followed up by Thirteenth Step in 2003; then in 2004, Emotive—an album of radically re-worked cover songs titles. Shortly after Emotive's release, the band went on hiatus; Keenan returned to Tool and started up solo work under the band name Puscifer; and Howerdel released a solo album, Keep Telling Myself It's Alright, under the moniker Ashes Divide. Band activity was sporadic in the following years; the band reformed in 2010, and played live shows on and off between 2010 and 2013, but fell into inactivity after the release of their greatest hits album, Three Sixty, and a live album box set, A Perfect Circle Live: Featuring Stone and Echo in late 2013. However, the band reformed in 2017 to record a fourth album, Eat the Elephant, which was released on April 20, 2018.
Prone to downtime due to Keenan's other musical commitments, the band has featured a variety of musicians in the other roles throughout its alternating periods of activity and inactivity. The original incarnation of the band included Paz Lenchantin on bass, Troy Van Leeuwen on guitar, and Josh Freese on drums; though Primus drummer Tim Alexander had briefly stood in as a drummer prior to Freese in the band's initial live shows prior to releasing any material. Band collaborator and producer Danny Lohner and Marilyn Manson bassist Jeordie White were also members for a short period in the early 2000s. The band's current lineup features Smashing Pumpkins guitarist James Iha, bassist Matt McJunkins, and drummer Jeff Friedl, the latter two also being contributors to the related Puscifer and Ashes Divide projects. Despite the varied cast and numerous lineup changes, the stylistic content of A Perfect Circle's songs has remained consistent with Howerdel as music composer, and Keenan writing lyrics and vocal melodies. The band's studio albums have been generally well received critically and commercially, with their three studio albums selling 4 million copies collectively as of 2005.
A Perfect Circle was originally conceived by Billy Howerdel, a former guitar technician for Nine Inch Nails, The Smashing Pumpkins, Fishbone and Tool. Howerdel met singer Maynard James Keenan in 1992, when Tool was opening for Fishbone, and the two became friends. Three years later, Keenan offered Howerdel, who was looking for lodging, a room in his North Hollywood home. This provided Howerdel the opportunity to play demos of his music for Keenan. Pleased with what he heard, Keenan remarked, "I can hear myself singing ." Although he originally desired a female vocalist, Howerdel agreed that Keenan would be a good fit, and A Perfect Circle was formed a short time later. The two rounded out the band's initial lineup with bassist and violinist Paz Lenchantin, former Failure guitarist Troy Van Leeuwen, and Primus drummer Tim Alexander. The band played their first show at LA's Viper Club Reception in August 1999, followed by a larger-scale, more widely publicized show at the Coachella Festival the following October. While initially in talks to release the album on Volcano Records – Tool's record label – Keenan stated that they instead chose to go with Virgin Records, who Keenan felt better understood that Keenan meant for the band to be an equally important band to Tool, not a minor side project. After the initial shows and securing a record deal, the band entered the studio to begin work on their first album. Alexander was soon replaced with Josh Freese, who previously worked with Howerdel on the Guns N' Roses album Chinese Democracy, with Alexander's only studio contribution being drums on the album version of the song "The Hollow.
The band's music has been described as a number of different genre, though despite the sound changes and lineup changes, the writing process has remained the same for the band; Howerdel primarily writes the band's instrumental music, while Keenan contributes the lyrics and vocal melodies.