https://www.youtube.com/watch?v=CQ6DBhMF5S0 Isolated vocals of "My heart will go on" performed by Celine Dion
https://www.youtube.com/watch?v=CUmOFqQRkco Original commercial release of "My heart will go on" performed by Celine Dion

Since you're working with a famous song, it's easiest to start with the song and work to the A Capella vocals than from the vocal track toward a backing track. I suggest the following steps.

.Open RealBand
. Import both audio files
. Mute the isolated vocals
. Analyze the commercial release version of the song with the ACW to create the chord chart, tempo map and determine the key signature
. Un-mute the Isolated vocal track and align and sync the isolated vocals with the commercial release version vocals
. Audition and select an appropriate BIAB style for the song
. Mute or erase the commercial version audio file
. Play and enjoy your BIAB version of Celine Dion performing "My Heart Will Go On"...

BIAB 2025:RB 2025, Latest builds: Dell Optiplex 7040 Desktop; Windows-10-64 bit, Intel Core i7-6700 3.4GHz CPU and 16 GB Ram Memory.