This was written by Henry Mancini for the TV series Peter Gunn, which ran from 1958-1961 and used this song performed by Henry Mancini and His Orchestra as its theme. Released as a single in 1958, the song didn't chart, but in 1959 Mancini's album The Music From Peter Gunn, featuring the theme, became the most popular album of the year, spending 10 weeks at #1.
Emerson, Lake & Palmer often used this song to open their shows (their version can be heard on their 1979 album In Concert). "'Peter Gunn' has got this sort of great satisfying feeling when you're playing it, because it is simple," Carl Palmer said in his Songfacts interview. "It's not very technical, but it means a lot. It gets right to the point. It's a great piece of writing. Musically, it works on keyboards or guitars or both."
There was also a practical reason why ELP used it to start their concerts: It's a relatively straightforward song that uses lots of frequency bands, which makes it a good one for sound engineers to work with as they try to sort out the mix.
Keith Noel Emerson (2 November 1944 – 11 March 2016) was an English keyboardist, songwriter, and record producer. He played keyboards in a number of bands before finding his first commercial success with the Nice in the late 1960s.
He became internationally famous for his work with the Nice, which included writing rock arrangements of classical music.
After leaving the Nice in 1970, he was a founding member of Emerson, Lake & Palmer (ELP), one of the early progressive rock supergroups. Emerson, Lake & Palmer were commercially successful through much of the 1970s, becoming one of the best-known progressive rock groups of the era.
Emerson wrote and arranged much of ELP's music on albums such as Tarkus (1971) and Brain Salad Surgery (1973), combining his own original compositions with classical or traditional pieces adapted into a rock format.