This brings us to one of the most remarkable features of "Idomeneo," which at the time rendered the work a true phenomenon, and which even now excites admiration and appears worthy of study: the treatment of the orchestra. It was to be expected that Mozart, having at his disposal a well-appointed and excellently trained orchestra, would develop with partiality the instrumental side of his great work. In point of fact, the orchestral portions of "Idomeneo" are richer, more brilliant, and more carefully carried out, even to the smallest details, than was ever again the case in his later works. The composition of the orchestra is quite the same as that which he employed in after-times, except that he occasionally has four horns, as on some former occasions (Vol. I., p. 304; II., p. 86), but not in Vienna. He disposed freely of all the forces at his command, not contenting himself any longer with accentuating different parts by means of richer instrumentation, but maintaining throughout a more brilliant and forcible instrumental colouring, and allowing the choice and use of means to be determined only by the particular subject which was to be represented. In this manner he kept himself within the bounds of moderation, and reserved certain resources for definite effects; for instance, flutes are employed only in the storm (18), trombones only for the oracle (28). In the choruses to "König Thamos," on the contrary, the trombones are in frequent use, as they were later with similar effect in the "Zauberflöte." So decidedly had Mozart even at that time fixed the character of this instrument. But he was particularly careful so to distribute his effects that the ear should never be either over-excited or over-fatigued. For instance, in the two storm scenes (5, 18) there are no trumpets and drums; they first occur in the flight scene, which is quite different in character; and again in the dance choruses (10, 32), when festive brilliancy is required; also in the mourning chorus, where they are muffled, which modifies the effect in a very original manner. These observations might advantageously be carried into detail; but it will suffice here to point out that Mozart's {IDOMENEO.} (160)