"Because rhythm 28 is not implemented by MT-32/CM-32L, they become silent. But Munt play that wrong event, so it sounds "bang"." -> wrong. I've tracked down exclusive message before ending. Rhythm 28 defined by this exclusive, with wrong parameter. Address 03 01 20 -> 03 50 07 07 Last "07" is wrong. It must be "00" or "01" (Reverb Switch). MT-32 sounds this patch, but LAPC-I never.
Ultima VII ending & Munt = wrong BANG