Frequently (and justifiably) associated with Celtic music, singer and songwriter Loreena McKennit has also incorporated Arabian, Moroccan, and Spanish influences into her distinct style.
Make no mistake, this is not really Nu Ambient music - it is a different way of fusing many of the same musical elements. In place of drum machines, you will hear a myriad of hand percussion. Acoustic instruments are the rule, rather than the exception. It often finds the soulfulness of New Age music, but is perfectly willing to go to darker places.
McKennitt's popularity and musical maturity grew through the 90's, peaking with significant radio play of The Mummers' Dance in 1997. According to the Wikipedia, she experienced a personal tragedy in 1998, and I assume that this is the cause of her 9-year recording hiatus. A new album is on the horizon, though.