Robert Rich is one of the more well known ambient artists going around (even though I always get him confused with Steve Roach, and bizarrely enough, Steve Reich), and Rainforest was his major breakthrough album and still his most famous, however unimaginative the title is. But that's 80's New Age marketing for you.
But it sounds exactly like its title; it's a rainforest! Lots of tribal drums, flutes and general jungle noises. It is interesting to note, that Rich designed the tracks around a 'natural' tuning system he created, away from the traditional Western scales. To me, it barely sounds different, but I'm not a musicologist.
Still, the more upbeat tracks are somewhat stereotypical, almost New Age. There is nothing particularly wrong with that, but I've heard it all before. It's the slower songs that are far better. Songs such as Sanctuary and The Raining Room (dedicated to brilliant Russian director Andrei Tarkovsky, for the record) have more depth and resonance then their rhythmic counterparts.
But the best song on the album is also the longest; Veil of Mist, which clocks in at nearly 11 minutes. It's a fusion centrepiece of the rest of the album, slow drums, wailing saxophones, and emotive piano.
Rainforest won't win any awards for anything (other than most popular 80's ambient album outside of Enya *shudders*), but it's good enough. Not a heavyweight, and Rich would mature away from the New Age scene after this, but Rainforest is passable for what it is.