Question: What do Markus Feehily and Ian Gillan have in common?

full_context: Document 1: Westlife: Westlife were an Irish boy band, formed in Dublin in July 1998 and disbanded in June 2012. Originally signed by Simon Cowell and managed by Louis Walsh, the group's second and final line-up consisted of Nicky Byrne, Kian Egan, Mark Feehily, and Shane Filan. Brian McFadden was a member from July 1998 until his departure in March 2004.
Document 2: Ronan Keating: Ronan Patrick John Keating (born 3 March 1977) is an Irish recording artist, singer, musician, and philanthropist. He debuted in 1994 alongside Keith Duffy, Michael Graham, Shane Lynch, and Stephen Gately, as the lead singer of Irish group Boyzone. His solo career started in 1999 and has recorded nine albums. He gained worldwide attention when his single "When You Say Nothing at All" was featured in the film "Notting Hill" and peaked at number one in several countries. As a solo artist, he has sold over 20 million records worldwide alongside the 25 million records with Boyzone, and in Australia, he is best known as a judge on "The X Factor" from 2010 until 2014 and a coach on "The Voice" in 2016. Keating is active in charity work and has been a charity campaigner for the Marie Keating Foundation, which raises awareness for breast cancer and is named after his mother who died from the disease in 1998.
Document 3: Markus Feehily: Markus Michael Patrick Feehily (formerly known as Mark Feehily, born 28 May 1980) is an Irish singer and songwriter. He was one of the lead singers of the boy band Westlife from 1998 to 2012.
Document 4: Ian Hunter (singer): Ian Hunter Patterson (born 3 June 1939), known as Ian Hunter, is a British singer-songwriter who is best known as the lead singer of the English rock band Mott the Hoople, from its inception in 1969 to its dissolution in 1974, and at the time of its 2009 and 2013 reunions. Hunter was a musician and songwriter before joining Mott the Hoople, and continued in this vein after he left the band. He embarked on a solo career despite ill health and disillusionment with commercial success, and often worked in collaboration with Mick Ronson, David Bowie's sideman and arranger from the "Ziggy Stardust and the Spiders from Mars" period.
Document 5: Ian Astbury: Ian Robert Astbury (born 14 May 1962) is an English singer and songwriter. He is best known as a founding member and the lead vocalist for the rock band The Cult.
Document 6: Ian Gillan: Ian Gillan (born 19 August 1945) is an English singer and songwriter. He originally found commercial success as the lead singer and lyricist for Deep Purple.
Document 7: Born Again (Black Sabbath album): Born Again is the eleventh studio album by English heavy metal band Black Sabbath, released in August 1983. It is the only album the group recorded with lead vocalist Ian Gillan, best known for his work with Deep Purple. It was also the last Black Sabbath album for nine years to feature original bassist Geezer Butler, and drummer Bill Ward, until he played the studio tracks on their 1998 live album "Reunion". The album has received mixed to negative reviews from critics, but it was a commercial success upon its 1983 release, reaching No. 4 in the UK charts. The album also hit the top 40 in the United States.
Document 8: Ian Curtis: Ian Kevin Curtis (15 July 1956 – 18 May 1980) was an English singer-songwriter and musician. He is best known as the lead singer and lyricist of the post-punk band Joy Division. Joy Division released their debut album, "Unknown Pleasures", in 1979 and recorded their follow-up, "Closer", in 1980.
Document 9: Fire (Markus Feehily album): Fire is the debut solo studio album by Irish singer-songwriter and former Westlife vocalist Markus Feehily. The album was released on October 16, 2015, via Harmoney Entertainment, as part of the Kobalt Music Group. The album includes the singles "Love is a Drug" and "Butterfly".
Document 10: Stephen Gately: Stephen Patrick David Gately (17 March 197610 October 2009) was an Irish pop singer-songwriter, actor, children's writer and dancer, who, with Ronan Keating, was one of two lead singers of the pop group Boyzone. Gately and Keating originally served as co-frontmen, but Keating gradually became more synonymous with the group as time went on. All of Boyzone's studio albums hit number one in the United Kingdom, their third being their most successful internationally. With Boyzone, Gately had a record-breaking sixteen consecutive singles enter the top five of the UK Singles Chart. He performed for millions of fans globally. He released a solo album in 2000, after the group's initial break-up, which charted in the UK top ten and yielded three UK hit singles, including the top three hit "New Beginning". Gately went on to appear variously in stage productions and on television programmes as well as contributing songs to various projects. In 2008, he rejoined his colleagues as Boyzone reformed for a series of concerts and recordings.
Document 11: Marti Pellow: Marti Pellow (born Mark McLachlan; 23 March 1965) is a Scottish singer. He was the lead singer of the Scottish pop group Wet Wet Wet from their formation in 1982 until their first split in 1997, and again from their reformation in 2004 to their second split in 2017. He has also recorded albums as a solo artist, and performed as an actor in musical theatre productions in both the West End and on Broadway.
Document 12: Gillan's Inn: Gillan's Inn is an album by Ian Gillan in celebration of his 40 years as a singer. The first release was a DualDisc composed of both a CD and a DVD side. The CD featured re-recorded tracks from all eras of Ian Gillan's singing career. In a recent interview Gillan observed that, despite the number of participants and guest appearances, this was the easiest project he ever put together.
Document 13: Love Is a Drug (Markus Feehily song): "Love Is a Drug" is a song by Irish singer and songwriter and former member of Westlife Markus Feehily. The song was released in the United Kingdom as a digital download On 19 April 2015 through Harmoney Entertainment. It was released as the lead single from his debut studio album "Fire" (2015). The song was written by Markus Feehily, Steve Anderson and Tinashé Fazakerley; and produced by Mojam. The song has peaked at number 65 on the Irish Singles Chart and number 55 on the UK Singles Chart.
Document 14: Shane Filan: Shane Steven Filan (born 5 July 1979) is an Irish singer and songwriter. He was one of the lead singers and frontman of boy band Westlife until the group disbanded in 2012. After the group disbanded, Filan released his debut solo album, "You and Me", in 2013.
Document 15: The Javelins: The Javelins, sometimes also known as Ian Gillan & the Javelins, was a 1960s band fronted by Ian Gillan of Deep Purple. The band played live but never recorded in their initial spell together. The other members included rhythm guitarist Tony Tacon, bass player Tony Whitfield,drummer Keith Roach and lead guitarist Gordon Fairminer. All from Hayes/Heston area of West London.
ground_truth: singer and songwriter