After its initial success in 1974, it reached number one in 1982 because it was part of a hit movie soundtrack. After this, in 1992, an extremely popular singer on the Pop Charts and in R&B, asked the song writer if she could sing the song in an upcoming movie she was starring in and it became a number one single again; most of her fans didn't have a clue that it had already hit number one twice. This actress/singer passed away un-expectantly in 2012, which helped the song hit number one on the charts yet again.
Maybe you've figured out by now that the writer of this song is Dolly Parton and the song was: "I'll Always Love You." Dolly gave the famous Porter Wagner credit for launching her career and she felt terrible about leaving The Porter Wagner show but she had to move on to work on her music career. She wrote the song in honor of him. This was in 1974. In 1982, she starred in the movie: "The Best Little Whorehouse in Texas," and she performed the song again and it hit number one.
Dolly is a prolific songwriter; not only songs for herself, but many of her songs have reached "The Top 10" on the music charts that have been sung by other artists. In all, she's credited for writing a little over 3,000 songs. If this weren't enough, she's one of the most successful business women in history.