English National Opera Guides are ideal companions to the opera. They provide stimulating introductory articles together with the libretto and illustrations. Although it is impossible to trace any one particular theme running through the operas of Michael Tippett, the libretti of his four operas are fascinating to compare. The dense allusions of
The Midsummer Marriage
(1955), here annotated, gave way to the classical formality of
King Priam
(1962); the psycho-analytical preoccupations of
The Knot Garden
(1970) hardly foreshadow the contemporary political commentary of
The Ice Break
(1977). Each work breaks new ground and provokes unexpected responses. The libretti offer unique introductions to the music. They incidentally throw a searching light on the direction of British theater since 1945.