Throughout the ending sequence of Ultima VI only one song plays. However, when watching the ending of the DOS version on YouTube three songs play: one at the beginning (Hail Britannia?), one when the Gargoyles arrive (the same as in the Gargoyle world) and finally when both kings read the Codex the last song plays, which is the one that plays throughout the entire sequence in Nuvie.
This was fixed in r1996.