This appears to be what I'm thinking of. Pretty similar to the one you described. A posthumous release from producer Nujabes called Spiritual State.
He was a japanese "nu-jazz" (whatever that is) producer who lays the beat with a variety of hip-hop acts lending verses. A friend of mine was banging on about this two years ago but I never got round to listening to it.
Might listen to both this and the one you recommended.