Problem: Background: Yusuf Islam (born Steven Demetre Georgiou; 21 July 1948), commonly known by his former stage name Cat Stevens, is a British singer-songwriter and multi-instrumentalist. His 1967 debut album reached the top 10 in the UK, and the album's title song "Matthew and Son" charted at number 2 on the UK Singles Chart. Stevens' albums Tea for the Tillerman (1970) and Teaser and the Firecat (1971) were both certified triple platinum in the US by the RIAA. His musical style consists of folk, pop, rock, and Islamic music.
Context: Immediately following the September 11 attacks on the United States, he said:  I wish to express my heartfelt horror at the indiscriminate terrorist attacks committed against innocent people of the United States yesterday. While it is still not clear who carried out the attack, it must be stated that no right-thinking follower of Islam could possibly condone such an action. The Qur'an equates the murder of one innocent person with the murder of the whole of humanity. We pray for the families of all those who lost their lives in this unthinkable act of violence as well as all those injured; I hope to reflect the feelings of all Muslims and people around the world whose sympathies go out to the victims of this sorrowful moment.  He appeared on videotape on a VH1 pre-show for the October 2001 Concert for New York City, condemning the attacks and singing his song "Peace Train" for the first time in public in more than 20 years, as an a cappella version. He also donated a portion of his box-set royalties to the fund for victims' families, and the rest to orphans in underdeveloped countries. During the same year, he dedicated time and effort in joining the Forum Against Islamophobia and Racism, an organisation that worked towards battling misconceptions and acts against others because of their religious beliefs or their racial identity (or both), after many Muslims reported a backlash against them due in part to the grief caused by the events in the United States on 11 September.
Question: What is significant about September 11 for Cat Stevens?
Answer: He appeared on videotape on a VH1 pre-show for the October 2001 Concert for New York City, condemning the attacks and singing his song "Peace Train

IN: Def Leppard are an English rock band formed in 1977 in Sheffield as part of the new wave of British heavy metal movement. Since 1992, the band has consisted of Joe Elliott (lead vocals), Rick Savage (bass, backing vocals), Rick Allen (drums, backing vocals), Phil Collen (lead and rhythm guitar, backing vocals), and Vivian Campbell (rhythm and lead guitar, backing vocals). This is the band's longest lasting line-up. The band's strongest commercial success came between the early 1980s and the early 1990s.

Rick Savage, Tony Kenning, and Pete Willis, all students at Tapton School in Sheffield, South Yorkshire, formed a band called Atomic Mass in 1977. The band originally consisted of Willis on guitar, Savage on bass (after originally playing guitar), and Kenning on drums. Only 18 at the time, Joe Elliott tried out for the band as a guitarist following a chance meeting with Willis after missing a bus, in November 1977. During his audition it was decided that he was better suited to be the lead singer. Their first ever gig was in the dining hall in A Block in Westfield School in Mosborough, Sheffield.  The band adopted a name proposed by Elliott, "Deaf Leopard", which was originally a band name he thought up while writing reviews for imaginary rock bands in his English class (and in at least partial reference to Led Zeppelin). At Kenning's suggestion, the spelling was slightly modified in order to make the name seem less like that of a punk band. In January 1978, Steve Clark joined the band. According to Elliott, he successfully auditioned for the band by playing Lynyrd Skynyrd's "Free Bird" in its entirety.  In November, just prior to recording sessions for what would be a three-song release known as The Def Leppard E.P., Kenning abruptly left the band; he would later form the band Cairo. He was replaced for those sessions by Frank Noon. By the end of the month, Rick Allen, then only 15 years old, had joined the band as its full-time drummer. Sales of the EP soared after the track "Getcha Rocks Off" was given extensive airtime by renowned BBC Radio 1 DJ John Peel, considered at the time to be a champion of punk rock and new wave music.  Throughout 1979, the band developed a loyal following among British hard rock and heavy metal fans and were considered among the leaders of the new wave of British heavy metal movement. Their growing popularity led to a record deal with the major label Phonogram/Vertigo (Mercury Records in the US). Def Leppard's original management, MSB, a local duo consisting of Pete Martin and Frank Stuart-Brown, were fired after Martin and Joe Elliott got into a fistfight over an incident on the road. The band approached Peter Mensch of Leber-Krebs management, who had booked them on a tour of the UK supporting AC/DC. Mensch, who admitted that he had had his eye on the band, became their manager.

Did this turn into Def Leppard?

OUT: The band adopted a name proposed by Elliott, "Deaf Leopard

Background: Gorillaz are an English virtual band created in 1998 by musician Damon Albarn and artist Jamie Hewlett. The band consists of four animated members: 2-D (lead vocals, keyboards), Murdoc Niccals (bass guitar), Noodle (guitar, keyboards), and Russel Hobbs (drums and percussion). These members are fictional and are not personas of any "real life" musicians involved in the project. Their fictional universe is explored through the band's music videos, as well as a number of other short cartoons.
Context: Musician Damon Albarn and comic book artist Jamie Hewlett met in 1990 when guitarist Graham Coxon, a fan of Hewlett's work, asked him to interview Blur, a band Albarn and Coxon had recently formed. The interview was published in Deadline magazine, home of Hewlett's comic strip Tank Girl. Hewlett initially thought Albarn was "arsey, a wanker"; despite becoming acquaintances with the band, they often did not get on, especially after Hewlett began seeing Coxon's ex-girlfriend Jane Olliver. Despite this, Albarn and Hewlett started sharing a flat on Westbourne Grove in London in 1997. Hewlett had recently broken up with Olliver and Albarn was at the end of his highly publicised relationship with Justine Frischmann of Elastica.  The idea to create Gorillaz came about when Albarn and Hewlett were watching MTV. Hewlett said, "If you watch MTV for too long, it's a bit like hell - there's nothing of substance there. So we got this idea for a cartoon band, something that would be a comment on that." The band originally identified themselves as "Gorilla" and the first song they recorded was "Ghost Train" which was later released as a B-side on their single "Rock the House" and the B-side compilation G Sides. The musicians behind Gorillaz' first incarnation included Albarn, Del the Funky Homosapien, Dan the Automator and Kid Koala, who had previously worked together on the track "Time Keeps on Slipping" for Deltron 3030's eponymous debut album.  Although not released under the Gorillaz name, Albarn has said that "one of the first ever Gorillaz tunes" was Blur's 1997 single "On Your Own", which was released for their fifth studio album Blur.
Question: were they together?
Answer:
Hewlett had recently broken up with Olliver and Albarn was at the end of his highly publicised relationship with Justine Frischmann of Elastica.