Question: What instrument did the singer of If I Could Change the World study?

full_context: Document 1: A Change Is Gonna Come: ``A Change Is Gonna Come ''Single by Sam Cooke from the album Ai n't That Good News A-side`` Shake'' Released December 22, 1964 (1964 - 12 - 22) Format 7 - inch single Recorded January 30, 1964 Studio RCA, Hollywood, California Genre Rhythm and blues soul Length 3: 12 Label RCA Victor Songwriter (s) Sam Cooke Producer (s) Hugo & Luigi Sam Cooke singles chronology ``Cousin of Mine ''(1964)`` A Change Is Gonna Come'' (1964) ``It's Got The Whole World Shakin '''(1965)`` Cousin of Mine'' (1964) ``A Change Is Gonna Come ''(1964)`` It's Got The Whole World Shakin''' (1965)
Document 2: Eric Clapton: After being discharged, it was recommended by doctors of Hazelden that Clapton not partake in any activities that would act as triggers for his alcoholism or stress. A few months after his discharge, Clapton began working on his next album, against doctors' orders. Working with Tom Dowd, he produced what he thought as his "most forced" album to date, Money and Cigarettes. Clapton chose the name of the album "because that's all I saw myself having left" after his first rehabilitation from alcoholism.In 1984 he performed on former Pink Floyd member Roger Waters' solo album, The Pros and Cons of Hitch Hiking, and joined the supporting tour. Since then Waters and Clapton have had a close relationship. In 2005 they performed together for the Tsunami Relief Fund. In 2006 they performed at the Highclere Castle, in aid of the Countryside Alliance, playing two set pieces of "Wish You Were Here" and "Comfortably Numb". Clapton, now a seasoned charity performer, played at the Live Aid concert at John F. Kennedy Stadium in Philadelphia on 13 July 1985, playing with Phil Collins, Tim Renwick, Chris Stainton, Jamie Oldaker, Marcy Levy, Shaun Murphy, and Donald 'Duck' Dunn. When offered a slot close to peak viewing hours, he was apparently flattered. As Clapton recovered from his addictions, his album output continued in the 1980s, including two produced with Phil Collins, 1985's Behind the Sun, which produced the hits "Forever Man" and "She's Waiting", and 1986's August.
Document 3: Change the World: ``Change the World ''is a song written by Tommy Sims, Gordon Kennedy, and Wayne Kirkpatrick whose best - known version was recorded by the British recording artist Eric Clapton for the soundtrack of the 1996 film, Phenomenon. The track was produced by R&B record producer Kenneth`` Babyface'' Edmonds. The single release, Clapton recorded for Reprise and Warner Bros. Records, reached the Top 40 in twenty countries and topped the charts in Canada as well as Billboard magazine's Adult Contemporary and Adult Top 40 charts in the United States. The single was prized with eight awards, among them three Grammy Awards, Clapton took home at the 39th annual ceremony in 1997.
Document 4: Constant Change: Constant Change is the sixth studio album by Filipino singer-songwriter Jose Mari Chan. It was released in the Philippines on May 25, 1989 by Universal Records. The album has produced "Beautiful Girl", "Please Be Careful with My Heart", "My Girl, My Woman, My Friend" and "I Have Fallen in Love (With the Same Woman Three Times)". In the same year, it won the Best Album on the Awit Awards. It is considered to be the first ever OPM album to reach the Diamond status by the Philippine Association of the Record Industry (PARI), and is currently the second biggest-selling album in the Philippines with sales of over 800,000 units in the country.
Document 5: Waiting on the World to Change: ``Waiting on the World to Change ''Single by John Mayer from the album Continuum Released July 11, 2006 Format CD digital download Recorded June 2006 Genre Blue - eyed soul pop rock blues rock Length 3: 18 Label Aware Columbia Sony Songwriter (s) John Mayer Producer (s) Steve Jordan John Mayer John Mayer singles chronology`` Go!'' (2005) ``Waiting on the World to Change ''(2006)`` Belief'' (2006) ``Go! ''(2005)`` Waiting on the World to Change'' (2006) ``Belief ''(2006) Limited edition EP cover art
Document 6: London: London was instrumental in the development of punk music, with figures such as the Sex Pistols, The Clash, and Vivienne Westwood all based in the city. More recent artists to emerge from the London music scene include George Michael, Kate Bush, Seal, Siouxsie and the Banshees, Bush, the Spice Girls, Jamiroquai, Blur, The Prodigy, Gorillaz, Mumford & Sons, Coldplay, Amy Winehouse, Adele, Ed Sheeran and One Direction. London is also a centre for urban music. In particular the genres UK garage, drum and bass, dubstep and grime evolved in the city from the foreign genres of hip hop and reggae, alongside local drum and bass. Black music station BBC Radio 1Xtra was set up to support the rise of home-grown urban music both in London and in the rest of the UK.
Document 7: London: London has numerous venues for rock and pop concerts, including the world's busiest arena the o2 arena and other large arenas such as Earls Court, Wembley Arena, as well as many mid-sized venues, such as Brixton Academy, the Hammersmith Apollo and the Shepherd's Bush Empire. Several music festivals, including the Wireless Festival, South West Four, Lovebox, and Hyde Park's British Summer Time are all held in London. The city is home to the first and original Hard Rock Cafe and the Abbey Road Studios where The Beatles recorded many of their hits. In the 1960s, 1970s and 1980s, musicians and groups like Elton John, Pink Floyd, David Bowie, Queen, The Kinks, The Rolling Stones, The Who, Eric Clapton, Led Zeppelin, The Small Faces, Iron Maiden, Fleetwood Mac, Elvis Costello, Cat Stevens, The Police, The Cure, Madness, The Jam, Dusty Springfield, Phil Collins, Rod Stewart and Sade, derived their sound from the streets and rhythms vibrating through London.
Document 8: Robin Blaze: The son of Peter, a professional golfer, and Christine, Robin Blaze, with his brother Mark, grew up in Shadwell, near Leeds, and was educated at Leeds Grammar School, Uppingham School, and Magdalen College, Oxford. Having made his first solo recordings as a treble with Stephen Lomas, Blaze was both a chorister and an academical clerk at Magdalen College where he recorded with the Dufay Consort. After graduating, he won a scholarship for postgraduate studies at the Royal College of Music, where he continued to study with Michael Chance and Ashley Stafford. After completing his education, he took a position as professor of Vocal Studies at the Royal College. He has also studied flute, piano, and organ.
Document 9: Mandolin: Mandolin has also been used in blues music, most notably by Ry Cooder, who performed outstanding covers on his very first recordings, Yank Rachell, Johnny "Man" Young, Carl Martin, and Gerry Hundt. Howard Armstrong, who is famous for blues violin, got his start with his father's mandolin and played in string bands similar to the other Tennessee string bands he came into contact with, with band makeup including "mandolins and fiddles and guitars and banjos. And once in a while they would ease a little ukulele in there and a bass fiddle." Other blues players from the era's string bands include Willie Black (Whistler And His Jug Band), Dink Brister, Jim Hill, Charles Johnson, Coley Jones (Dallas String Band), Bobby Leecan (Need More Band), Alfred Martin, Charlie McCoy (1909-1950), Al Miller, Matthew Prater, and Herb Quinn.
Document 10: Stevie Blacke: Born in London and raised in Ohio, Blacke grew up with the music of Eric Clapton and Pink Floyd, before he attended the Berklee College of Music to study guitar, mandolin and violin. He learned and first recorded cello during a session for a hip hop artist.
Document 11: Queen (band): In 1999, a Greatest Hits III album was released. This featured, among others, "Queen + Wyclef Jean" on a rap version of "Another One Bites the Dust". A live version of "Somebody to Love" by George Michael and a live version of "The Show Must Go On" with Elton John were also featured in the album. By this point, Queen's vast amount of record sales made them the second best selling artist in the UK of all time, behind the Beatles. In 2002, Queen were awarded the 2,207th star on the Hollywood Walk of Fame, which is located at 6358 Hollywood Blvd. On 29 November 2003, May and Taylor performed at the 46664 Concert hosted by Nelson Mandela at Green Point Stadium, Cape Town, to raise awareness of the spread of HIV/AIDS in South Africa. May and Taylor spent time at Mandela's home, discussing how Africa's problems might be approached, and two years later the band was made ambassadors for the 46664 cause.
Document 12: Steve Smith (American Dad!): A freshman at Pearl Bailey High School, Steve is a highly capable musician, having taken up the cello to once impress a girl. In a later episode, however, Steve says that he has been playing the cello since he was nine. Steve also plays guitar and sings, which he did as part of a band in the episode ``American Dream Factory. ''In fact, both of the songs Steve's band rehearses (`` Livin 'on the Run'' and ``Sunset Blvd ''), were originally recorded by Scott Grimes, who voices Steve. Among Steve's other talents are being able to read Elvish, use Morse code, and communicate with dolphins.
Document 13: We Are the World: ``We Are the World ''is a song and charity single originally recorded by the supergroup United Support of Artists (USA) for Africa in 1985. It was written by Michael Jackson and Lionel Richie (with arrangements by Michael Omartian) and produced by Quincy Jones for the album We Are the World. With sales in excess of 20 million copies, it is one of the fewer than 30 all - time physical singles to have sold at least 10 million copies worldwide.
Document 14: Wonderful Tonight: ``Wonderful Tonight ''is a ballad written by Eric Clapton. It was included on Clapton's 1977 album Slowhand. Clapton wrote the song about Pattie Boyd. The female vocal harmonies on the song are provided by Marcella Detroit (then Marcy Levy) and Yvonne Elliman.
Document 15: Eric Clapton: Clapton was born on 30 March 1945 in Ripley, Surrey, England, to 16-year-old Patricia Molly Clapton (7 January 1929 – March 1999) and Edward Walter Fryer (21 March 1920 – 15 May 1985), a 25-year-old soldier from Montreal, Quebec. Fryer shipped off to war prior to Clapton's birth and then returned to Canada. Clapton grew up believing that his grandmother, Rose, and her second husband, Jack Clapp, Patricia's stepfather, were his parents, and that his mother was actually his older sister. The similarity in surnames gave rise to the erroneous belief that Clapton's real surname is Clapp (Reginald Cecil Clapton was the name of Rose's first husband, Eric Clapton's maternal grandfather). Years later, his mother married another Canadian soldier and moved to Germany, leaving young Eric with his grandparents in Surrey.Clapton received an acoustic Hoyer guitar, made in Germany, for his thirteenth birthday, but the inexpensive steel-stringed instrument was difficult to play and he briefly lost interest. Two years later Clapton picked it up again and started playing consistently. Clapton was influenced by the blues from an early age, and practised long hours to learn the chords of blues music by playing along to the records. He preserved his practice sessions using his portable Grundig reel-to-reel tape recorder, listening to them over and over until he felt he'd got it right.In 1961, after leaving Hollyfield School in Surbiton, Clapton studied at the Kingston College of Art but was dismissed at the end of the academic year because his focus remained on music rather than art. His guitar playing was so advanced that, by the age of 16, he was getting noticed. Around this time, Clapton began busking around Kingston, Richmond, and the West End.
ground_truth: violin
sub_queries: who sings if i could change the world Answer: Eric Clapton
Eric Clapton >> instrument Answer: violin