Conductor Vassil Arnaudov, who died in 1991, was a huge influence on the 40-strong women's choir, helping it build a broad repertoire, from European renaissance-baroque polyphony to 20th century music, and turning many Bulgarian choral works into masterpieces. There is light piano accompaniment on a few of these 23 pieces, but the emphasis is on the lilting, soaring soprano voices with their crystal-clear diction, that dance over difficult passages with grace and polished ease. Some of our favorites are the title tune, Schubert's "Die Nachtigall," Thomas Morley's "Good morrow, fair ladies of the May," Beethoven's "Ich liebe dich," Philip Koutev's "Draguna and the nightingale," Verdi's "Laudi alla Vergine Maria" and Mozart's "Ave verum corpus," but each piece is beautifully realized. A special collection of choral music by one of the best choirs in Europe, directed by the brilliant conductor who brought them to that place.