When Mozart received the commission for Idomeneo and began work on the opera, he knew that he would be writing for some of the best singers in Europe and for one of its finest orchestras. The principal tenor was to be Anton Raaff (Idomeneo), then aged sixty-six and at the end of a career that had started with study under Bernacchi in the late 1730s. He had worked with Jommelli in Vienna, dominated tenor roles in Italy in the 1760s, and concluded his career in the service of Karl Theodor in Mannheim and Munich. While he was at Mannheim in the 1770s, Raaff shared the stage with Dorothea Wendling (Ilia), who was considered by the aesthetician Christian Schubart and Wilhelm Heinse, the novelist, to be one of Europe's finest sopranos. Christoph Wieland thought her superior even to the famous Gertrud Elisabeth Mara. The wife of Dorothea Wendling's brother-in-law, Elisabeth Wendling (Elettra), had been praised by Leopold Mozart in 1763. Since four participants in the premiere of Idomeneo were named Wendling, a fragment of their family tree is given as Figure 3.1.

The orchestra was effectively the same that had so impressed Charles Burney among others. In August 1772 he described it in words that have since become famous: ‘There are more solo orchestra in Europe; it is an army of generals, equally fit to plan a battle, as to fight it.’