Question: What instrument besides guitar and mandolin was studied by the original singer of Let it Rain?

full_context: Document 1: 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.
Document 2: Let It Down: "Let It Down" is a song by English musician George Harrison, released on his 1970 triple album "All Things Must Pass". The recording was co-produced by Phil Spector and employs the latter's Wall of Sound production technique to lavish effect. Its brash opening and choruses contrast with the ethereal quality of the verses – a loud/soft approach that has been credited with influencing indie bands during the 1980s and 1990s.
Document 3: Let It Be: ``Let It Be ''is a song by the English rock band the Beatles, released in March 1970 as a single, and (in an alternate mix) as the title track of their album Let It Be. At the time, it had the highest debut on the Billboard Hot 100, beginning its chart run at number 6. It was written and sung by Paul McCartney. It was their final single before McCartney announced his departure from the band. Both the Let It Be album and the US single`` The Long and Winding Road'' were released after McCartney's announced departure from and the subsequent break - up of the group. The alternate mix on their album Let It Be features an additional guitar solo and some minor differences in the orchestral sections.
Document 4: Let It Be: ``Let It Be ''is a song by the English rock band the Beatles, released in March 1970 as a single, and (in an alternate mix) as the title track of their album Let It Be. At the time, it had the highest debut on the Billboard Hot 100, beginning its chart run at number 6. It was written and sung by Paul McCartney. It was their final single before McCartney announced his departure from the band. Both the Let It Be album and the US single`` The Long and Winding Road'' were released after McCartney's announced departure from and the subsequent break - up of the group.
Document 5: 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 6: 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 7: Let It Rain (Eric Clapton song): ``Let It Rain ''is a song and single written and released by the British rock musician Eric Clapton of his 1970 debut studio album Eric Clapton. It is the third and last single that had been released of the album.
Document 8: Eric Clapton: Eric Patrick Clapton, CBE (born 30 March 1945), is an English rock and blues guitarist, singer, and songwriter. He is the only three - time inductee to the Rock and Roll Hall of Fame: once as a solo artist and separately as a member of the Yardbirds and Cream. Clapton has been referred to as one of the most important and influential guitarists of all time. Clapton ranked second in Rolling Stone magazine's list of the ``100 Greatest Guitarists of All Time ''and fourth in Gibson's`` Top 50 Guitarists of All Time''. He was also named number five in Time magazine's list of ``The 10 Best Electric Guitar Players ''in 2009.
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: 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 11: Let It Rain (Mark Chesnutt song): "Let It Rain" is a song co-written and recorded by American country music artist Mark Chesnutt. It was released in March 1997 as the second new single from his "Greatest Hits" album. The song reached number 8 on the U.S. "Billboard" Hot Country Singles & Tracks chart and peaked at number 16 on the Canadian "RPM" Country Tracks chart. It was written by Chesnutt, Roger Springer and Steve Leslie.
Document 12: 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 13: Clapton (2010 album): Clapton is the eighteenth solo studio album by English rock guitarist and singer-songwriter Eric Clapton. It was released on 27 September 2010 in the United Kingdom and the following day in the United States.
Document 14: Bruce Molsky: As a young man, Molsky first became interested in blues music, but eventually became absorbed in old-time music while studying engineering at Cornell University in Ithaca, New York, beginning in 1972. His playing was influenced by the fiddling of Tommy Jarrell, whom Molsky visited in North Carolina in 1976. He recorded with Bob Carlin in 1990.
Document 15: 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.
ground_truth: violin
sub_queries: who sang the original version of let it rain Answer: Eric Clapton
Eric Clapton >> instrument Answer: violin