More than any other non-compilation CD I have, Macross Plus OST II can be best described as "eclectic". There's such a wide, unusual variety of musical styles here that it's impossible to characterize the disc with any other single word. While Macross Plus OST I focuses mostly on the orchestral score and other dramatic music, OST2 throws in the remainder of BGM from the OAVs, which ranges from pop to jazz to even high-pitched be-bop.
The more conventional tracks are the most musically entertaining and memorable. Among these, "Pulse" stands out most. Combining beautifully-tambered, pleasurably melodic, mostly non-lyrical vocals with modern instrumentation, the track avoids the pitfall cliches of both western pop and J-pop to emerge progressive yet enjoyable. In exposing the track to others I've found it appeals to all sorts, soundtrack fans and non-fans alike.
"Idol Talk" is another pop song, bouncier than Pulse but more similar to standard pop fare. "Voices (Acoustic version)" is yet another fantastic version of the oh-so-memorable Macross Plus theme... no rehashing here. This one has only a piano for the instrumental accompaniment, which makes the gentle beauty of the vocals even more apparent.
Beyond those three tracks, things get a little less predictable. Highlights include "A sai en", the wicked, piercing a cappella vocal piece from Sharon Apple, which is immortalized to Mac Plus fans as the music during the next-episode preview at the end of each video. Then there's "Jade", an amusing and entirely unusual track consisting mostly of contrasting heavy percussion and lighthearted whistling. Like several other tracks, although it can be briefly heard during the videos, much of its music goes unnoticed until heard separately on the CD release.
A few other musical pitstops along the way include the jazzy "Nomad Soul", the twangy acoustic guitar of "Welcome to Sparefish", the piano-sax combo in "3 cm" that could fit straight into the bar scene of an old-time detective movie, and the immensely peculiar sampled vocals of "Bad dog". Short of describing each track individually, there's no way to even marginally describe the styles present.
So does all the musical variety add up to a CD worth purchasing? For fans of the videos, the answer is undoubtedly yes. It's a real treat hearing the diverse musical tidbits that occur throughout the series - even more so when you discover those tidbits are actually full-fledged, thoroughly developed musical arrangements. As for those unfamiliar with the videos, the question is less simple, and I can't honestly answer with certainty because I'm a self-proclaimed Macross Plus fanatic. My recommendation would be to start with OST1 unless you're feeling adventuresome, since it gives a more consistent musical picture of the series and is more in line with traditional soundtracks. Then if you like what you hear, pick up OST2 to get a fuller idea of Macross Plus's soundscape and Kanno-san's compositional diversity.