Based on the first two editions, published in 1947 and 1965, of Donald Grout (d.1987, musicology, Cornell U.), the third (1988) and fourth editions have been revised and updated by Williams (Hamilton College). New to the fourth edition is a reorganization of the section on the 20th century into geographical areas, new sections on national traditions in the US and the countries of the former Soviet Union, and substantial revision based on recent research. Among the countries included in the discussion of 20th-century works are Greece, Turkey, the Netherlands, Denmark, Sweden, Finland, Spain, Portugal, Latin America, and Australia. A substantial (100-page) bibliography (organized by chapter) and index are provided. Annotation (c) Book News, Inc., Portland, OR (booknews.com)