Here is an experiment I just completed a few minutes ago and the results.

I have a solo rhythm guitar track that varies between 106 - 114 bpm according to ACW results. (I didn't record it -- Promise)

I imported the track into track 1 of RealBand. Executed ACW using the existing song and answered no to the keep existing bars question since I want ACW to develop the tempo map.

The ACW determined the chords, progression and tempo. The average tempo was 107.xxx I can't recall the exact number but it's not necessary since my intent is to use a whole number for the tempo. The chords were imported onto the chord chart.

My first attempt resulted in the chords not being in proper alignment so I ran the track through the ACW again and reset the first bar and imported the ACW results back into RB.

I selected the whole track and opened the time shift/pitch correct menu and ran it on the track setting the old tempo at 106 and the new tempo at 107.

Once that process completed, from the tempo map radio button I set the tempo at a fixed 107bpm.

Because of the variance in BPM's of the original track, I selected the entire track and made a minor alignment of the first chord with the first bar.

My track was now aligned at the fixed 107bpm. But the chords were now off by a bar because of the alignment. I had to re-enter the chord chart. However, near the end of the song, again, I believe due to such a large variance of bpm of the original track, the chords began to drift off from the proper bar alignment. It drifted about two measures of the four measure bar.

If I was planning to use this as John mentioned above with his choir director tracks, I would split the track and move the remaining measures back two beats and time stretch the last bar before the split so that any RB/BB generated RT's would be in time.

But looking for other solutions, in the EDIT/track menu was the option to align a track recorded 'free time' to a click track. I attempted this but the click track must be a 'C' note. I generated a generic click track in Audacity that RB could not read.

According to the help file, this advanced feature will likely accomplish what John would like to do with his choir director's recordings without jumping through all the hoops I jumped through.

I'll eventually try the alignment with click feature to see for myself.

BIAB Ultra Pak+ 2024:RB 2024, Latest builds: Dell Optiplex 7040 Desktop; Windows-10-64 bit, Intel Core i7-6700 3.4GHz CPU and 16 GB Ram Memory.