"Losing My Mind" was first performed by Dorothy Collins in the role of "Sally Durant Plummer" in the original Broadway production of Follies. Other performers who have sung the song in later productions of Follies include Barbara Cook (1985), Julia McKenzie (1987), Donna McKechnie (1998), Judith Ivey (2001), Victoria Clark (2007),and Bernadette Peters (2011).
The song has been covered by many artists including Shirley Bassey and Michael Ball.
The song was written as a torch song for the character of Sally to sing in the "Loveland" portion of the musical. The song "expresses her preoccupation with Ben, her idealized lover...With infinite attention to detail, Sondheim leads Sally from sunrise to sleepless night, revealing that every second of her existence is defined by her longing...the number ...explores the extent to which she has lost herself in this make-believe world of undying desire." As originally staged, Sally comes onstage in a "clinging, beaded silver" dress, holding a microphone. The "cute" Sally from Phoenix "has become a languid torch singer." She repeats her lines, reflecting "the paralysis about which she sings...the phrase 'It's like I'm losing my mind' occurs no less than six times."
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