Subject says it all. The second OAV series was largely disappointing, even in the music department, but there were a few very striking tracks that I really wanted to get my hands on. I will list what I can remember:
1: Episode four ('The Advent of the Goddess'

, when Tokimi makes her appearance, an ominous little tune gets played.
2: Same episode, when Ryouko gets captured.
3: Episode five ('Zero Ryoko'

, when Tenchi and pals make their unprecedented escape from Dr. Clay's collapsing ship, a more upbeat rendition of tune #1 above is played.
I recall owning Ongaku-hen #3, which had some of the BGM from this series, but I do not recall hearing ANY of the above three tunes on it.
I've been made aware of a box set which contains all the music from the first OAV series which had not previously been made available. Fine. Where's the series two version of that? Which CD has this music?