This is actually due to Final Fantasy VI Pixel Remaster's music resources for those scenes being copied japanese tracks instead of instrumental like they should... While this isn't really an issue on my end per se, it would be great if this could get fixed.
Fixing this would either require removing the option to pick instrumental tracks or require some sort of workaround and use the instrumental resource that has opera scenes playing together back to back for use in the game's Sound Test.
Changes:
32b --> 32(approx. from 1:40 to 2:23)
34c --> 34(approx. from 2:27 to 3:09)
33 is not affected