Oviously there will be different ways to do this task, but I would appreciate hearing about your approach.

Let's say you have a clean vocal file (a cappella, without background music).

Since it is a famous song, like My heart will go on, so more or less, you already know the chords of the song.

From this point onwards, how do you proceed to make a backing track, using BIAB and other tools?

My sincere thanks,

do you know the key and the bpm timing? if both are spot on you could do it but otherwise it might be a problem. maybe someone else can advise on using the ACW in BIAB?

if you do know the key and bpm exactly. you could create a backing track in BIAB without the vocal.

then open it in RealBAnd and import the vocal track as a wav file. if the synch is a bit off you can slide the vocal track. if the pitch is a bit off you can pitch transpose the vocal.

i'm sure its possible in BIAB but I find RB much more transparent and easier to use

My approach would be to find an appropriate Style and Tempo in BB. Then add the Chords and get a fairly good layout (Arrangement you like) for the song. Then put the BB file to the correct key (to suit the vocals). Don’t worry if they are not spot on at this stage.

Then I’d be inclined to export the tracks into a DAW and get a good rough mix. Add the vocal track and if needed use something like Melodyne to address vocal tuning discrepancies. (In Reaper there are other tools you can use and/or move track items up or down by a few cents.). Then do a final mix add reverb, eq, compression or whatever and then as a final do a little limiting to lift the track to the appropriate level.

It really depends on the tools you have but a lot you can do very cheaply.

My thoughts
Tony

Was the vocal recorded to a click track?

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"...

The easiest and quickest way:

All within BIAB

File: import the audio
open Audio edit
select marker mode: Audio chord wizard
check Auto marking
add a couple of bar lines from start that matches the song
bar lines are automatically added for the song, check if ok and adjust if necessary
use equalize tempos if you need to stabilize the tempo
run analyze and chords will be detected
switch to chord sheet
adjust chords and for song structure, e.g. verse/chorus with A/B markers
you're done if the pitch of the audio was ok

if not, you need to correct the pitch.
There is a pitch shift tool under Audio, but with limited functionality, i.e. if the pitch is drifting in the audio it will just be a compromise to minimize the flaws

There are other softwares that can correct the pitch where it is needed in the audio file.

I think it took me longer to write this than it would to get a first draft of the complete song with the audio + the added backing tracks.

I've used this feature quite a lot with older audio recordings and it's really good!
But there is always room for improvements ...

cheers Thomas