Originally recorded by Kasey Cisyk (US #80 1977).
Other hit versions by Debby Boone (US #1/CAN #1/UK #48 1977), LeAnn Rimes (US#34/C&W #48 1997).
From the wiki: “Kasey Cisyk’s work singing commercial jingles brought her to the attention of Joe Brooks, who worked as a composer and arranger of jingles. Brooks, who wrote, directed and composed the score for the movie You Light Up My Life chose Cisyk to dub the singing voice of actress Didi Conn.
“Cisyk’s performance of the song appears on the original soundtrack album, and was released as a single, although she was not listed as the performing artist in the final credits of the film (for which she successfully sued the producers). Her single release of the song reached #80 on the Billboard Hot 100 charts.
“The song was later recorded by singer Debby Boone, with Brooks producing and arranging. This recording of ‘You Light Up My Life’ was to become the #1 single on the Billboard chart for ten consecutive weeks. People magazine ran a substantial article about ”The real voice’ behind ‘You Light Up My Life” inasmuch the similarity between her and Debby Boone’s voice led many to assume the latter had sung the songs in the movie.
“In a 2013 biographical essay about Cisyk, Cisyk’s second husband, Ed Rakowicz (who worked professionally as a sound engineer, but not for this song), wrote that songwriter Brooks was initially pleased with Cisyk’s recording of the song with orchestra but ‘tried to evade payment by false promises and by asking her to be an incidental actor in his film, implying huge rewards yet to come…’ Rackowicz claimed that Brooks made improper advances toward Cisyk, and after being rebuffed, didn’t speak directly to her again, and continued to evade payments to her while commissioning another recording with Debby Boone. (Brooks would later be indicted, in 2009, on 91 counts of rape, criminal sexual act, and other charges.) According to Rackowicz, ‘Besides wanting Boone to copy Kacey’s [sic] iconic hit reading of his songs, Brooks needed to cover up Kacey’s vocal leakage in the microphones in the piano recorded at the original demo session on which was overdubbed the orchestral track used in the film. Brooks didn’t want to pay to re-record the piano and orchestra again.
“In a 2003 interview with Entertainment Weekly, Boone said, ‘I had no freedom whatsoever. Joe told me exactly how to sing it and imitate every inflection from the original recording.’ Cisyk later retained a lawyer and sued Brooks for the fees she earned for her work on the record and for credit on the soundtrack, which she later received.
“Cisyk was the daughter of two Ukrainian immigrants. Her father, Volodymyr Cisyk, a well known Ukrainian concert violinist and teacher, taught his daughter the violin when she was 5 years old, grooming her for a career as a classical musician. Cisyk’s original goal was a career as an opera singer, but her father’s death left the family without a source of income. Needing to earn money immediately, Cisyk pursued a career as a session singer in popular music, working as a backup singer for Carly Simon and Michael Franks and for artists produced by Quincy Jones. Cisyk achieved her widest success as a singer of the musical jingles used in TV and radio commercials. Cisyk’s recording of the slogan ‘Have you driven a Ford lately?’ was used in Ford commercials from 1981 to 1998; in 1989, Ford executives estimated that Cisyk’s recording of that phrase had been heard by 20 billion people.
“In 1980 she recorded her first album, Kvitka, Songs of Ukraine which won top honors in the 1988 Ukrainian Music Awards. Her second album, Kvitka, Two Colors, was released in 1989. Both albums were nominated for a Grammy Award for Best Contemporary Folk Album. Because of her contribution to Ukrainian music a yearly music festival is held and a street was named in her honor in Lviv, Ukraine.”
Kasey Cisyk, “Have You Driven a Ford, Lately?” (1984):
Debby Boone, “You Light Up My Life” TV performance (1977):
LeAnn Rimes, “You Light Up My Life” (1997):