This volume serves as a comprehensive, portable reference tool designed to provide quick access to essential information regarding the history, terminology, and key figures of the operatic tradition. Harold Rosenthal and John Warrack leverage their extensive expertise in musicology to synthesize a vast array of facts into a single, accessible format. The text functions as a foundational resource for both casual listeners and dedicated students of the genre who require immediate clarification on specific works, composers, or technical vocal concepts.

Experts and music historians frequently cite this work as a reliable, high-density reference for standard operatic knowledge. Readers note that the prose is concise and utilitarian, making it a standard fixture for those seeking rapid verification of facts in the field of classical music.