Semele is a masterpiece. For what else can one call a drama in which the perfect symbiosis of text and music conjures up such suggestive power? 'To hold the mind, the ears and the eyes equally spellbound': this recommendation by La Bruyère (Les Caractères: 'Les ouvrages de l'esprit') refers to the 'machine plays' so adored by the public in the Baroque period. But even without machinery or indeed without sets or real staging, Handel's oratorio involves us in the tragic fate of his heroine with supreme skill.