for awhile they lumped anything instrumental that wasn't kenny G type shit as "Acid Jazz" . i used to be into Acid jazz when i was on the east coast. they had a lot of clubs for it. the music ranged from stuff like Brand new heavies on the commercial end to all kinds of undergorund stuff, including a lot of underground hip-hop. I was feeling hip-hop influenced acts like Massive attack and Portsihead too. Portisheads beats sounded kind of like Rza with musical training. Both albums are classics. i still listen to a lot of chillout ( the latest marketing buzzword' they are using.
If you get a chance, get the dub version of Massive Attack's Protection album. It was done by the Mad porfessor and is called "no protection".