David Rothenberg's latest CD, five years in the making, finds cutting-edge musicians from all over the world mixing their sounds with the wonderful musical melodies and tones of birds. The CD coincides with his new book "Why Birds Sing," published by Basic Books in April which has already sold 15,000 copies. Rothenberg's clarinets and Michael Pestel's flute meet a white-crested laughing thrush in the National Aviary, and a wild Australian lyrebird named George in his rainforest home. "David Rothenberg," says Paul Winter, "is one of the rare musicians who is devoted to exploring the voices of the natural world. I would hope this work might encourage others to follow suit."