Article snapshot taken from Wikipedia with creative commons attribution-sharealike license.
Give it a read and then ask your questions in the chat.
We can research this topic together.
"Theme from S.W.A.T." is an instrumental song written by Barry De Vorzon and performed by American funk group Rhythm Heritage, released on their debut album Disco-Fied. It reached number one on the Billboard Hot 100 singles chart in the United States on the chart date of February 28, 1976.
As the title implies, it was the opening theme music for the 1970s American television series S.W.A.T., though it is a noticeably different recording from the actual TV theme version, which was performed not by Rhythm Heritage, but by Barry De Vorzon's own orchestra with arrangement by Dominik Hauser. The theme song was also referenced by characters in the 2003 motion picture of the same name, who mouth the notes during a party to celebrate their successful completion of the training course. De Vorzon's original was eventually released on the LP Nadia's Theme on Arista records.
In 1994, S.W.A.T. released a version titled "Theme From SWAT"— sung by Jerry A. of Poison Idea, with sampled LAPD radio broadcasts from the April 1992 riots— on their album Deep Inside: A Cop's Mind.
In 2003, Rap group Hot Action Cop used the song as template for a song titled "Samuel Jackson" which was used as the theme to the film adaptation of S.W.A.T., starring Samuel L. Jackson.
In 2011, a remix version of the song was performed by composer John Paesano, appeared in the opening credits of S.W.A.T.: Firefight.
In 1976 Ray Conniff and his orchestra had mild success with their cover of "The Theme from SWAT" on Columbia Records.
In 1990 the Italian DJ and Producer Piero Fidelfatti, sampled a part of the main theme and made a house version of "Theme From S.W.A.T." (Magic Service/Discomagic MS001)
In 1991 the rap group 3rd Bass sampled the instrumental in a remixed version of their song "3rd Bass Theme a.k.a. Portrait of the Artist as a Hood" on Def Jam Recordings.