Birdsongs of the Mesozoic was formed in the early 80s by Roger Miller, formerly of Mission of Burma. You might as well forget that connection because they sound absolutely NOTHING like Mission of Burma. BOTM is completely unclassifiable, playing some of the craziest music you will ever hear. They're completely angular, eccentric, avant garde, and unpredictable. You could probably classify their later stuff as "jazz", as they becamse more normal over the years, but even then that's a bit of a stretch. At their best, they sound like nothing else. I really can't explain it, so I'll just let the music speak for itself.
I have two earlier songs and one later one for your musical enjoyment. This first one is one of my absolute faves by them, called "Shinty Golden Snakes." Dig the cheesy drum machine actually making the song sound more on the edge.
My Trusted MOGs
BOTM have done some interesting things over the years, but I think one of the greatest is this cover of the theme song to "Rocky and Bullwinkle."
My Trusted MOGs
This is a later recording. Roger Miller is gone, replaced by other musicians. The avant garde is still there, but more jazz inspired. As a whole, it's not as satisfying, but there are some bright spots. The first song on Petrophonics, for example, kicks a whole lot of buttooty.
My Trusted MOGs
I like the first track a lot! I like the offbeat thing mixed in with the "random" noises!
I don't even remember the rocky and bullwinkle song, but that song is great! I love those keys! And the distant fuzzy guitar and the even more distant fuzzy snare!
The last one... it sounds like a bad Devo song or something similar in that vein. The jazz is highly more noticeable, and I guess that adds to it. Almost like Kenny G rockin out!
My Trusted MOGs
I don't know if I'd go so far as to say Kenny G, but I know what you mean. The sax has started to dominate, and frankly that usually is a bad thing in a rock setting, to me. Not that I have anything against saxophones, but it adds a texture that tends to sound a bit wimpy to me. I like that track, but it's the best one on the album by far. The other two, as you noted, are far more interesting. Their older stuff is so worth it, if you can find it.