Answer by taking a quote from the following article:

David Jon Gilmour,  (born 6 March 1946) is an English guitarist, singer and songwriter best known as a longtime member of the progressive rock band Pink Floyd. He joined the group as guitarist and co-lead vocalist in 1968, effectively as a replacement for founder member Syd Barrett, who was dismissed from the band shortly afterwards. Pink Floyd subsequently achieved international success with the concept albums The Dark Side of the Moon, Wish You Were Here, Animals, and The Wall. By the early 1980s, they had become one of the most critically acclaimed and best-selling acts in the history of popular music; it was estimated that by 2012 the band had sold over 250 million records worldwide, including 75 million units sold in the United States.

Gilmour was responsible for bringing Kate Bush to public attention. While she was still at school, her family produced a demo tape with over 50 of her compositions, which was turned down by record labels. Gilmour received a copy of the demo from Ricky Hopper, a mutual friend of Gilmour and the Bush family. Impressed with what he heard, Gilmour helped the sixteen-year-old Bush get a more professional-sounding demo tape recorded that would be more saleable to the record companies. Three tracks in total were recorded and paid for by Gilmour. The tape was produced by Gilmour's friend Andrew Powell (who would go on to produce Bush's first two albums) and sound engineer Geoff Emerick. Gilmour then arranged for EMI executive Terry Slater to hear the tape. Slater was impressed by the tape and signed her.  Gilmour is credited as executive producer on two tracks on her debut album The Kick Inside, including her second single "The Man with the Child in His Eyes". He performs backing vocals on "Pull Out the Pin", on her fourth album, The Dreaming, and plays guitar on "Love and Anger" and "Rocket's Tail" on her sixth, The Sensual World.  In March 1987, Bush, notorious for the rarity of her live performances, sang "Running Up That Hill" at The Secret Policeman's Third Ball with Gilmour on guitar. A three DVD set of The Secret Policeman's Balls benefit concerts that includes their performance was released in 2009. In 2002, she performed "Comfortably Numb", singing the part of the doctor, at Gilmour's concert at the Royal Festival Hall in London.

Who is Kate Bush?
Gilmour was responsible for bringing Kate Bush to public attention. While she was still at school,