Olivier Messiaen's Catalogue d'Oiseaux, or Catalogue of Birds, is one of the most ambitious works of the modern era, at least in terms of its sheer length and complexity. It comprises 13 pieces, one of which, La Rousserolle Effarvatte (The Reed Warbler), takes up the entire second CD of this three-disc set. The music evokes not only birdsong but the appearance of birds, their behavior at various times of year, and even their characteristic habitat in France, all the while holding to a brutal level of technical challenges and to his own serialist-influenced tonal idiom. It is program music for the modern era, at once descriptive and abstract. It is not for the faint-hearted, and the list of pianists who have attempted it is short. Pierre-Laurent Aimard, who studied with Messiaen and with his wife, Yvonne Loriod, has a strong claim to know how the music should sound, and for nonspecialist listeners he does much to clarify the swirl of sound, to bring out the descriptive details that are sometimes hidden between several layers of music, and to shape the rather lengthy individual sections. Sample La Merle de roche (The Rock Thrush) for an idea of the depth of Aimard's achievement. A highly recommended survey of a major 20th century work.