This reference work serves as a comprehensive guide to the history, terminology, and key figures within the field of opera. The authors, Harold Rosenthal and John Warrack, leverage their extensive expertise in musicology to compile a structured lexicon that defines essential terms, identifies major composers, and outlines the significance of specific operatic works. The text provides a systematic framework for navigating the complex nomenclature and historical development of the genre.

Experts and music historians frequently cite this volume as a foundational reference tool for students and enthusiasts of the operatic arts. Readers often note the clarity of the entries and the precision of the historical data provided throughout the text.