"The Complete Opera Book" by Gustav Kobbé is a guide to operas first published posthumously in 1919. This comprehensive reference presents opera stories alongside musical notation of leading airs and motives. Covering works from Gluck to early twentieth-century composers, the book organizes operas by national schools and historical periods. Originally left unfinished at Kobbé's death, it was completed by editor Katharine Wright and expanded through numerous editions, becoming the definitive encyclopedic account of opera for generations of music lovers and record collectors.