"Sounds from a Secret Garden" is one of the albums I keep at the office to defend me from the nattering and chattering of others -- played on a Discman of course. It's refreshingly well-conceived aural wallpaper in the same class as the Holberg Suite by Edvard Grieg (that's high praise, by the way) and the double CD "Opium" by Ottmar Liebert + Luna Negra.
This is not music for sitting down and listening to deliberately, but it really works as background to conversation, work or relaxing with a book.