In 1976, what disco version of a U.S. TV show's theme song was #1 on the "Billboard" Hot 100 singles chart?

"Theme from S.W.A.T." is an instrumental song written by Barry De Vorzon (born July 31, 1934) 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 in February 1976.

As the title implies, it was the opening theme music for the 1970s American television series "S.W.A.T". 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. But is completely recognizable as the TV theme.

It remains one of a handful of TV themes to top the "Billboard" Hot 100, a list that includes "Welcome Back" from Welcome Back Kotter, "Miami Vice Theme" from Miami Vice and "How Do You Talk to an Angel" from Beverly Hills 90210.

"S.W.A.T." was an American action/crime drama television series about the adventures of a Special Weapons And Tactics (S.W.A.T.) team operating in an unidentified Californian city, although filming was done in and around Los Angeles.