Fortunately her husband convinced her to make a demo, even if she wasn't thrilled about it.
After Horner played Dion and her husband, the late René Angélil, the song, she was adamantly against it. Without Dion's husband, she never would have sung it.Without input from the studio or the director, the legendary composer went off and created the song all on his own with Dion's vocals in mind. James Horner wrote the song without anyone's knowledge.The initial buzz surrounding the lengthy film was dismal, but the insane popularity of the song gave ticket sales a much-needed boost. 28, 1998, helping the Titanic soundtrack land a 16-week run on top of the Billboard 200 (it remains one of only seven soundtracks to be certified diamond by the RIAA). Tommy Mottola, then-head of Sony Music Entertainment, claims that 'My Heart Will Go On' was conceptualized as a 'powerful marketing tool,' and if true, they knocked it out of the park. Titanic might not have been as popular at the box office without it.The director of Titanic envisioned ending his historical disaster epic with a standard score rather than a pop song, reportedly saying, 'Would you put a song at the end of Schindler's List?'
13 Fascinating Things You Probably Didn't Know About Titanic