Overture: Idomeneo K366

Idomeneo, which was first performed two days after Mozart’s 25th birthday in Munich in 1781, was a major turning point in the composer’s development. He had written astonishingly mature music before – like the Piano Concerto in E flat K.271 when he was no more than 21 and the Sinfonia Concertante in E flat K.364 three years later – but nothing on the scale of Idomeneo, which uniquely transforms the obsolescent ritual of opera seria into a thoroughly dramatic theatrical experience. Although it is set in ancient Greece and has little to do with anyone below the rank of prince or princess, it is remarkable above all for its understanding and expression of human emotions. The dilemma of Idomeneo, King of Crete, who finds that he is duty-bound to sacrifice his son to Neptune, is not one we meet every day but it is no less agonising for that.

The drama begins with the overture, which anticipates fears that will not be stilled until the end of the opera. It begins in regal splendour in D major but within seconds political stability is undermined by a subversively chromatic figure rising threateningly on a crescendo on the strings. At the same time woodwind instruments introduce a plaintive little motif which will later be associated with the private thoughts not only of Idomeneo but also of    his son Idamante and Ilia the Trojan princess who is in love with him. This material, so dramatically treated in terms of harmony and dynamics, is the main concern of the piece. Although there are other themes, offered as a gesture towards classical sonata form, they are not developed and when it comes to the recapitulation they are just left out, to make way for strings and woodwind as they quietly set the emotional scene for Ilia’s aria at the beginning of Act 1. The true ending of the overture comes only in the D major celebration of Idomeneo’s release from his cruel obligation in the final stage of the opera.