CLASSICAL Bizet, Georges: Symphony in C. Mozart, Wolfgang Amadeus: Serenade No. 11 in D , K. 251. National Arts Center Orchestra of Canada, Eduardo Mata, conductor. (RCA Red Seal Digital XRC1-4689) - This delightful record serves to introduce to a major label the National Arts Center Orchestra of Canada, one of this continent's very finest chamber orchestras. As heard in a Carnegie Hall concert this past December, and as heard on this exceptionally well-recorded disk, the orchestra plays elegantly, with a soothing, melting tone and considerable elegance of phrasing. If one likes the Bizet played brusquely and with rasor-sharp edges, this record will not be for you. If, however, you prefer a more classical approach to this Mozartean work, this is one of the best I've heard. The Mozart Serenade on the flip side only confirms what the Bizet suggests - this is as fine a chamber ensemble as any in the world today and deserves as widespread exposure on records as any of its British counterparts. Mata's work throughout is confident, stylish, engaging.