<< I've followed every step everyone suggested in this thread. There was either no change or it made the problem worse.>>
<< I appreciate the input and I will try the things Ian and Charlie suggested. >>

<< The swabbie one plays fine until you start to get in to the key change. It's painful after that. >>
<< The reason that this is happening is a combination of these two things (A) Band-in-a-Box generates the file based on the original key of your song. (B) RealTracks artists play what is natural for them to play for a chord in that style of music, so seeing a B chord in the key of A, many RealTracks will play the b7. >>

I reviewed where some of the suggestions have been attempted but didn't see any remarks to why the Song Medley Feature failed. Other than the fact that Medley Maker will not start a Medley in 3/4 time, using the Song Medley Feature: Tools| Song Form| --- Song Medley Maker will do exactly what you're asking BIAB to do. It can't 'not change' nor can it 'make it worse'.

The Song Medley Feature interprets and plays each of your song sections for what they are if you follow every step I detailed on 1/11/21; Individual BIAB song SGU files. The Song Medley Feature combines individual songs and creates transitions between them by creating a temporary SGU chart that can be saved and rendered to audio. The Song Medley Feature will play each song exactly as each individual 'song' is written - in the proper key signature, tempo, feel, genre, and chord progression. BIAB 'sees' and interpret the transition section of your song and you can manually change that transition to your specifications or you can manually create the transition and BIAB will ignore making an automatic transition by setting the transition period to (0).

It's established in other comments in this thread that your song will play the correct chords in any key up to the point the song modulates. So if you generate and save as a song, the Chord Chart in the key of -A- with no modulation programmed, all of the chords play correctly without the 7th. Then, if you generate and save as a song, the Chord Chart in the key of -B- with no modulation programmed, all of the chords play correctly without the 7th, it is a simple matter to program the transition from your choice of the multiple options to choose from, and have the BIAB Song Medley Feature play the two songs as the performance you're attempting to achieve. It's a simple matter to complete the Song Medley program instructions so that:

Song Medley will play the bars up to the transition of song 1 in -A- to the transition bar in the song.
Song Medley will Transition as programmed.
Song Medley will play the bars following the transition of song 2 in -B- to the end of the song.

It's also a simple process to start the song in 4/4 and transition to 3/4 for the actual song and have the transition be a small gap of silence to be edited and cut out after rendering the song to audio.

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.