Question: Where did the performer of Visions of the Beast form?

full_context: Document 1: British Lion (album): British Lion is the debut solo album from Steve Harris, best known as the bassist and primary songwriter for the British heavy metal band Iron Maiden. The album was announced on 18 July 2012 and released on 24 September.
Document 2: List of Iron Maiden concert tours: Iron Maiden are a British heavy metal band, founded in 1975 by bassist Steve Harris in London, England. After several personnel changes in the 1970s, the band settled on a lineup of Harris, Paul Di'Anno (lead vocals), Dave Murray (lead and rhythm guitars), Dennis Stratton (backing vocals, lead and rhythm guitar) and Clive Burr (drums), before they set out on their first professional tour, the Metal for Muthas Tour which supported the compilation album of the same name. After taking on a supporting slot with Judas Priest on their British Steel Tour and setting out on their own headline tour in support of their debut album, "Iron Maiden", the band supported Kiss on the European leg of their Unmasked Tour, following which Stratton was dismissed because of musical differences. Guitarist Adrian Smith was hired, following which Iron Maiden set out on a short series of UK dates before recording their second studio album, "Killers".
Document 3: Rock in Rio (album): The video release, which was issued on DVD, VHS and UMD, was edited by bassist and founder member Steve Harris. In addition to the concert, the second disc also includes three special features with interviews with band members, a short documentary on the day in the life of Iron Maiden, and photos by official photographer, Ross Halfin.
Document 4: Iron Maiden (album): Iron Maiden Studio album by Iron Maiden Released 14 April 1980 Recorded January 1980 Studio Kingsway Studios, London, England Genre Heavy metal Length 37: 35 Label EMI Harvest / Capitol (North America) Producer Wil Malone Iron Maiden studio albums chronology Iron Maiden (1980) Killers (1981) Killers 1981 1998 remastered version cover Singles from Iron Maiden ``Running Free ''Released: 8 February 1980`` Sanctuary *'' Released: 23 May 1980 * Not an original album track, but added to later editions
Document 5: Eddie's Archive: Eddie's Archive is a box set by British heavy metal band Iron Maiden, released on November 16, 2002. The box, an embossed metal casket featuring the face of mascot Eddie, contains three double CDs, the Iron Maiden family tree and a shot glass. The family tree is an updated version of the family tree that originally came with "A Real Dead One" in 1993.
Document 6: Classic Albums: Iron Maiden – The Number of the Beast: Classic Albums: Iron Maiden -- The Number of the Beast is a documentary about the making of the album of the same name by the British heavy metal band Iron Maiden, released on 26 November 2001 as part of the Classic Albums documentary series. Directed by Tim Kirkby, it featured cuts from the title track, ``Children of the Damned '',`` Run to the Hills'', and ``The Prisoner, ''in addition to extended interviews and live footage of`` Hallowed Be Thy Name'', recorded during the band's performance at the Rock in Rio festival in 2001.
Document 7: Beast over Hammersmith: Beast over Hammersmith is a live album by the British heavy metal band Iron Maiden, released on 4 November 2002. Recorded 20 years previously, during The Beast On The Road tour at the Hammersmith Odeon, the footage was specially co-produced and mixed by Steve Harris and Doug Hall to be a part of the Eddie's Archive box set. Even though this album contains material from "The Number of the Beast", it was actually recorded two days prior to its release (although "Run to the Hills" had already been released as a single).
Document 8: Little Box of Horrors: The box set contains all four full-length releases by the band, all with their original artwork (American version). It also contains a fifth disc, entitled "Rare Treats", which features demo versions of many songs, as well as other rare songs by the band. The American release is accompanied by a DVD, entitled "The Transvestite Chainsaw Massacre: Live '98", which features footage of 9 songs performed live at Ground Zero, in Spartanburg, South Carolina, in 1998.
Document 9: The Final Frontier: The Final Frontier is the fifteenth studio album by British heavy metal band Iron Maiden. It was released on 13 August 2010 in Germany, Austria and Finland, 17 August in North America, 18 August in Japan, and 16 August worldwide. At 76 minutes and 34 seconds, it is the band's second-longest studio album to date, a duration surpassed only by 2015's "The Book of Souls".
Document 10: Fear of the Dark (Iron Maiden album): Fear of the Dark is the ninth studio album released by English heavy metal band Iron Maiden. Released on 11 May 1992, it was their third studio release to top the UK albums chart and the last to feature Bruce Dickinson as the group's lead vocalist until his return in 1999.
Document 11: Virus (Iron Maiden song): "Virus" is a single from Iron Maiden, released in 1996. It is the first single since 1980's "Women in Uniform" that does not appear on any official Iron Maiden studio album. It was, however, featured as a brand new track on the band's first ever career retrospective — 1996's double-disc "Best of the Beast". It is the only Iron Maiden song to be credited to both of the band's guitarists. It has never been performed live by Iron Maiden, but Blaze Bayley performed it several times in his solo career. Lyrically, the song warns of rising business corruption in an increasingly Internet-dependent world.
Document 12: Iron Maiden: Iron Maiden are an English heavy metal band formed in Leyton, East London, in 1975 by bassist and primary songwriter Steve Harris. The band's discography has grown to thirty-nine albums, including sixteen studio albums, twelve live albums, four EPs, and seven compilations.
Document 13: Maiden Japan: Maiden Japan, also known as "Heavy Metal Army", is a live EP by the British heavy metal band Iron Maiden. The title is a pun of Deep Purple's live album "Made in Japan".
Document 14: Visions of the Beast: Visions of the Beast was released by Iron Maiden on 2 June 2003 and contains every promotional video through 2001's "Rock in Rio". It is basically an updated version of "" and "From There to Eternity". It also includes never-before-seen Camp Chaos animated versions of six definitive Iron Maiden songs, interactive menus and discographies, and some special hidden extras.
Document 15: Best of the Beast: Best of the Beast was Iron Maiden's first "best of" album, released in 1996 in three formats: a 34 track (four disc) vinyl, a 27 track (two disc) CD, a 16 track (single disc) CD and MiniDisc. The vinyl edition is, to date, the band's longest record release, running for over three hours.
ground_truth: Leyton
sub_queries: Visions of the Beast >> performer Answer: Iron Maiden
Iron Maiden >> location of formation Answer: Leyton