Question: what does Killers and Paul Di'Anno have in common?

Context articles: List of Iron Maiden concert tours
Di'Anno
Live at the Rainbow
Paul Di'Anno
Killers Live at the Whiskey
Di'Anno (album)
List of songs recorded by Iron Maiden
Gogmagog (band)
Killers (Iron Maiden album)
Purgatory (song)

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".
Di'Anno was a band featuring former Iron Maiden singer Paul Di'Anno, whom the band was named after.
Live at the Rainbow is the first live video recorded by Iron Maiden on 21 December 1980 and released in 1981.
 It includes one of the band's earliest concerts with guitarist Adrian Smith as well as a very early version of "Killers", with lyrics that differ from the album version that would be released in 1981.
 Paul Di'Anno later admitted writing the lyrics 5 minutes before going on stage that night.
Paul Andrews (born 17 May 1958), better known by his stage name Paul Di'Anno, is a British singer best known as the first vocalist to record with heavy metal band Iron Maiden, from 1978 to 1981.
Killers Live at the Whiskey is a live album by the former Iron Maiden singer Paul Di'Anno and his band Killers.
 The album was apparently recorded at the Whisky a Go Go club in Los Angeles however it is suspected that it was recorded in the studio with crowd noise mixed in the recording.
 The exact recording date is unknown.
 The title of the CD has been misspelled as the name of the club is actually written without the "e".
 The album contain songs from Di'Anno's solo career and four songs from his back catalogue with Iron Maiden.
Di'Anno is the 1984 self-titled album of the band of the same name.
 The lead singer Paul Di'Anno had been the frontman of the British heavy metal band Iron Maiden for three years, before being dismissed for his erratic behaviour.
 The band bearing his name and playing very commercial heavy rock was his first and short-lived solo project.
Iron Maiden are an English heavy metal band formed by bassist Steve Harris in 1975.
 The band's first album, 1980's "Iron Maiden", was written primarily by Harris, with vocalist Paul Di'Anno co-writing two tracks and guitarist Dave Murray contributing "Charlotte the Harlot".
 The 1981 follow-up, "Killers", was written almost entirely by the bassist, with frontman Di'Anno contributing only to the title track, "Killers" (the North American bonus track "Twilight Zone" was credited to Harris and Murray).
 Bruce Dickinson replaced Di'Anno after the release of "Killers", although he did not contribute any songwriting to "The Number of the Beast", released in 1982, which featured three songs co-written by guitarist Adrian Smith.
 "The Number of the Beast" also spawned Iron Maiden's first UK Singles Chart top ten in the form of "Run to the Hills", which charted at number seven on its release.
 It was not until 1983's "Piece of Mind" that the songwriting process became a more varied and collaborative approach, with just four of its nine tracks being credited solely to Harris, two to Dickinson and Smith, one to Harris and Murray, one to Dickinson alone, and one to Harris, Dickinson, and Smith.
 The Dickinson and Smith-penned "Flight of Icarus" was the first Iron Maiden single to chart in the United States, reaching number eight on the "Billboard" Mainstream Rock chart.
Gogmagog were a British supergroup put together by British record producer Jonathan King that featured former Iron Maiden members Paul Di'Anno and Clive Burr, former White Spirit and Gillan guitarist Janick Gers, Def Leppard guitarist Pete Willis, and bassist Neil Murray (Whitesnake and other bands).
 Two of the songs recorded were written by King; the third by composer Russ Ballard.
 Originally, the supergroup was to contain David Coverdale, John Entwistle and Cozy Powell, but this line-up "wasn't working out", according to Di Anno.
 He also insisted that he hated the finished product and that he "only did it for the money".
Killers is the second studio album by the English heavy metal band Iron Maiden, released on 2 February 1981 by EMI Records in the United Kingdom and on 6 June 1981 by Harvest Records and Capitol Records in the United States.
 The album was their first with guitarist Adrian Smith, and their last with vocalist Paul Di'Anno, who was fired after problems with his stage performance arose due to his alcohol and cocaine use.
 "Killers" was also the first Iron Maiden album recorded with the assistance of producer Martin Birch, who went on to produce their next eight albums up until "Fear of the Dark" (1992).
"Purgatory" is Iron Maiden's fifth single, released on 15 June 1981, and would be their last with singer Paul Di'Anno.
 It is the only single from "Killers" as the preceding release, "Twilight Zone", was not included on the album's original pressing.
 The single was reissued in 1990, on the same CD and 12" vinyl as the EP "Maiden Japan", in the "First Ten Years" box set.