The definitive solution to this is to install Band-in-a-Box 2019 version 608 (or newer), but installing the Roland/Cakewalk TTS1 synth is also a no-brainer good idea!

Build 608 is here...
https://www.pgmusic.com/forums/ubbthreads.php?ubb=showflat&Number=511571#Post511571

Info on the TTS-1 synth is here
https://www.pgmusic.com/forums/ubbthreads.php?ubb=showflat&Number=511593#Post511593


Have Fun!
Peter Gannon
PG Music Inc.