The 1974 film That’s Entertainment, was a surprise hit for MGM, placing in the top 20 movies of the year and resulting in a sequel in 1976. The movie showed clips of the studio’s library of great musicals, narrated by its former stars.: Fred Astaire; Gene Kelly; Elizabeth Taylor; and Frank Sinatra, among others, and were filmed as they walked through the old standing sets of the back lots 3 through 6.
Source: A VIRTUAL TOUR OF THE OLD M-G-M BACK LOTS – Silver Screen Modes by Christian Esquevin