An account of a life in the field organized around an illuminating, personal analysis of the songs of 30 North American birds (with accompanying CD). With line drawings, tables, charts and sound spectrograms. Kroodsma, professor emeritus at the University of Massachusetts, is especially interested in geographic variation in songs. Don Stap wrote about Don Kroodsma and his work in Birdsong.  (BRD22, $16.95)