You light up my life

"You Light Up My Life" is a ballad written by Joe Brooks and originally recorded by Kasey Cisyk for the soundtrack to the film of the same name. The song was performed in the film by its lead, Didi Conn, who lip synched Cisyk's version. Pat Boone's daughter, Debby Boone, was recruited to record the single, which became a massive success, topping the Billboard Hot 100 chart for a record-setting ten consecutive weeks. It easily became the most successful single of the 1970s in the United States and set a new Hot 100 record for longest reign at No.1. (Elvis Presley's double-sided "Don't Be Cruel/Hound Dog", then recognized as the longest-running No.1 of the Rock Era, spent 11 weeks atop the Billboard Best Sellers chart in 1956, before the debut of the Hot 100.) The record was matched in 1982 by Olivia Newton-John's Physical, but never surpassed until a 1991 change in chart methodology allowed songs to achieve longer reigns at No.1 ("End of the Road" by Boyz II Men set the new record, 13 weeks). The single, which was certified platinum by the RIAA, also hit #1 on the Adult Contemporary chart and even reached #4 on the Country chart. Although written by Brooks as a love song, the devout Boone interpreted the song as inspirational and proclaimed that it was instead God who "lit up her life."