Who co-produced the single with which Coldplay became popular?
Ken Nelson
Title: Soul music
Passage: Soul music (often referred to simply as soul) is a popular music genre that originated in the United States in the late 1950s and early 1960s.  It combines elements of African-American gospel music, rhythm and blues and jazz.  Soul music became popular for dancing and listening in the United States, where record labels such as Motown, Atlantic and Stax were influential during the Civil Rights Movement.  Soul also became popular around the world, directly influencing rock music and the music of Africa.
Title: A Rush of Blood to the Head
Passage: A Rush of Blood to the Head is the second studio album by the British rock band Coldplay.  It was released on 26 August 2002 by Parlophone in the United Kingdom, and a day later by Capitol Records in the United States.  The album was produced by the band and producer Ken Nelson.  Recording started after the band became popular worldwide with the release of their debut album "Parachutes" (2000), and one of its singles in particular, "Yellow".  The album makes greater use of electric guitar and piano than its predecessor.
Title: Yellow (Coldplay song)
Passage: "Yellow" is a song by the British rock band Coldplay.  The band wrote the song and co-produced it with British record producer Ken Nelson for their debut album, "Parachutes" (2000).  The song's lyrics are a reference to the band's lead singer Chris Martin's unrequited love.
Yellow (Coldplay song) A Rush of Blood to the Head