Question: Which rock band was formed first, Mazzy Star or A Perfect Circle?

<P0-S0> A Perfect Circle is an American rock supergroup formed in 1999 by guitarist Billy Howerdel and Tool vocalist Maynard James Keenan. <P0-S1>  A Perfect Circle has released three albums: their debut "Mer de Noms" in 2000, a follow up, "Thirteenth Step" in 2003, and an album of radically re-worked cover songs titled "Emotive" in 2004. <P0-S2>  Shortly after "Emotive"' s release, the band went into hiatus while Keenan returned to Tool and starting up solo work in the form of the band Puscifer, and Howerdel releasing a solo album, "Keep Telling Myself It's Alright", under the moniker Ashes Divide. <P0-S3>  Band activity was sporadic in the coming 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, "" in late 2013. <P0-S4>  However, in 2017, the band returned to touring and announced plans to record and release a fourth studio album under a new record label, BMG Rights Management, between late 2017 and early 2018. <SEP> <P1-S0> The discography of American alternative rock supergroup A Perfect Circle consists of three studio albums, two compilation albums, one extended play, one video album, nine singles, one promotional single and ten music videos. <P1-S1>  A Perfect Circle is the brainchild of Billy Howerdel. <P1-S2>  After hearing demos of Howerdel's music, Maynard James Keenan, the lead singer of Tool, offered his services as vocalist. <P1-S3>  Howerdel agreed, and the band formed in 1999. <P1-S4>  They were then joined by bassist/violinist Paz Lenchantin, guitarist Troy Van Leeuwen, formerly of Failure, and drummer Tim Alexander, formerly of Primus. <P1-S5>  Soon after entering the studio to record their first album, Alexander was replaced by Josh Freese of The Vandals. " <P1-S6> Mer de Noms" was released in May 2000, selling 188,000 copies its debut week. <P1-S7>  The band embarked on a number of headlining tours all over the world to promote the album which was certified gold by the Recording Industry Association of America (RIAA) one month after its release, and platinum just four months later. <SEP> <P2-S0> Ashes Divide is the name used for the solo project of American rock musician Billy Howerdel, guitarist of the alternative rock band A Perfect Circle, where he is the primary songwriter, musician, producer, and vocalist. <P2-S1>  The project's debut album, "Keep Telling Myself It's Alright", was released in 2008. <P2-S2>  Howerdel formed a live band and toured in support of the album through the rest of the year, but the project fell to the wayside after A Perfect Circle reformed and toured in 2010 and 2011. <P2-S3>  Howerdel would work on both projects for a while until late 2012, where he announced his primary focus is completing the second album, of which he hoped to enter the mixing phase in January or February 2013. <SEP> <P3-S0> Mazzy Star is an American alternative rock band formed in Santa Monica, California, in 1989 from the group Opal, a collaboration of guitarist David Roback and bassist Kendra Smith. <P3-S1>  Roback's friend Hope Sandoval became the group's vocalist when Smith left the band.