Question: The song "Masterpiece" is by this American singer and songwriter who is  widely cited as an influence by other artists and often referred to as what?

Context paragraphs:
Odetta: Odetta Holmes (December 31, 1930 – December 2, 2008), known as Odetta, was an American singer, actress, guitarist, songwriter, and a civil and human rights activist, often referred to as "The Voice of the Civil Rights Movement".  Her musical repertoire consisted largely of American folk music, blues, jazz, and spirituals.  An important figure in the American folk music revival of the 1950s and 1960s, she influenced many of the key figures of the folk-revival of that time, including Bob Dylan, Joan Baez, Mavis Staples, and Janis Joplin. " Time" magazine included her song "Take This Hammer" on its list of the 100 Greatest Popular Songs, stating that "Rosa Parks was her No. 1 fan, and Martin Luther King Jr. called her the queen of American folk music."

Turning point of the American Civil War: There is widespread disagreement among historians about the turning point of the American Civil War.  A turning point in this context is an event that occurred during the conflict after which most modern scholars would agree that the eventual outcome was inevitable.  While the Battle of Gettysburg in July 1863 is the event most widely cited as the military climax of the American Civil War (often in combination with the Siege of Vicksburg, which concluded a day later), there were several other decisive battles and events throughout the war which have been proposed as turning points.  These events are presented here in chronological order.  Only the positive arguments for each are given.

Masterpiece (Madonna song): "Masterpiece" is a song by American singer Madonna for the soundtrack of the 2011 film "W.E." The song was later included on her twelfth studio album "MDNA" (2012).  It served official radio release in the United Kingdom on April 2, 2012, to promote the album.  Madonna composed the song alongside Julie Frost and Jimmy Harry, and produced it with William Orbit.  "Masterpiece" is a midtempo pop ballad which is reminiscent of her works from the 1990s.  The song garnered positive reviews from contemporary critics, who praised its lyrical content and Madonna's vocal performance.

Madonna (entertainer): Madonna Louise Ciccone ( ; born August 16, 1958) is an American singer, songwriter, actress, and businesswoman.  A leading presence during the emergence of MTV in the 1980s, Madonna is known for pushing the boundaries of lyrical content in mainstream popular music, as well as visual imagery in music videos and on stage.  She has also frequently reinvented both her music and image while maintaining autonomy within the recording industry.  Besides sparking controversy, her works have been acclaimed by music critics.  Referred to as the "Queen of Pop", Madonna is widely cited as an influence by other artists.

Don Bradman: Sir Donald George Bradman, AC (27 August 1908 – 25 February 2001), often referred to as "The Don", was an Australian cricketer, widely acknowledged as the greatest batsman of all time.  Bradman's career Test batting average of 99.94 is often cited as the greatest achievement by any sportsman in any major sport.

Eric S. Raymond: Eric Steven Raymond (born December 4, 1957), often referred to as ESR, is an American software developer, author of the widely cited 1997 essay and 1999 book "The Cathedral and the Bazaar" and other works, and open-source software advocate.  He wrote a guidebook for the Roguelike game "NetHack".  In the 1990s, he edited and updated the Jargon File, currently in print as "The New Hacker's Dictionary".

A Gunshot to the Head of Trepidation: "A Gunshot to the Head of Trepidation", often referred to as "Gunshot", is a song by American heavy metal band Trivium.  Written by Matt Heafy and Corey Beaulieu, both of whom perform vocals and guitars on the track, it was featured on the band's second studio album "Ascendancy" in 2005.  The song was also released as a promotional single in May 2005, with an accompanying music video following in September.  "Gunshot" is often cited as one of the band's most popular songs, and has been performed at live shows consistently since its release.

Jolin Tsai: Jolin Tsai ( ; ; born September 15, 1980) is a Taiwanese singer, songwriter, dancer, actress, and businesswoman.  Known for reinventing both her music and image, she is cited as a huge role of popularizing dance music as mainstream music in Greater China.  Often referred to as the "Queen of C-pop", "Asia's Dancing Queen", and "Asian Madonna", she has achieved popularity in Chinese-speaking world by releasing a series of commercially and critically successful albums and has a dedicated fanbase worldwide.

Matt Henshaw: Matthew "Matt" Henshaw (born 10 September 1987) is an English musician, singer, and songwriter.  He first emerged in 2010 as a soul singer collaborating with numerous artists, cited as the NME Breakthrough Artist and compared to Smokey Robinson, Curtis Mayfield, Marvin Gaye and Al Green.  He has often cited his influences to be the likes of Sam Cooke, Otis Redding, Steve Marriott and Steve Winwood.

Gretchen (singer): Maria Odete Brito de Miranda, known as Gretchen; born May 29, 1959 in Rio de Janeiro) is a Brazilian singer, reality television personality, actress, and businesswoman.  She achieved popularity with the movie "Aleluia, Gretchen", which tells the story of a German Brazilian immigrant family.  Gretchen is known for reinventing both her music and representation, and for maintaining her autonomy within the music industry.  She has a vast musical repertory, and has been a source of some controversy throughout her career.  Referred to as the "Rainha do Bumbum" ("Queen of Butt"), Gretchen is often cited as an influence by other artists.

Supporting paragraphs: Masterpiece (Madonna song) Madonna (entertainer)
Answer: Queen of Pop