Most of the song in the film is Monroe’s own voice but she needed help in two phrases – “These rocks don’t lose their shape, diamonds are a girl’s best friend”, and at the beginning with a series of high-pitched “no’s”, all of which were dubbed in by the soprano Marni Nixon.
The number was later re-shot in CinemaScope, to be used as part of a CinemaScope demonstration held on the Fox lot in March of 1953. Producer Darryl F. Zanuck told “Daily Variety” that it only took 3-1/2 hours to shoot the number in CinemaScope versus four days for the original film version. The public finally saw the CinemaScope version ten years later when it closed Fox’s documentary tribute to Marilyn, however, this has not been released on DVD or VHS.
The song was listed as the 12th most important film song of all time by the American Film Institute.
Monroe’s rendition of the song has been considered an iconic performance and has since been copied by other entertainers ranging from Madonna and Kylie Minogue to Geri Halliwell and Anna Nicole Smith. Madonna’s video “Material Girl” uses a similar set and costumes for the singer and her male dancers.