Divertimento, in Italian, means "entertainment," or "diversion." Composers in the latter part of the eighteenth century used the term as a title for a wide variety of instrumental pieces whose primary purpose was to be light, pleasant, and entertaining. Divertimentos (or divertimenti, the frequently encountered Italian plural) usually have more than four movements sometimes as many as ten and often include minuets, marches, and theme-and-variation movements. The number of instruments generally varies from three to ten, and the instruments may be strings, winds, or a combination of the two.
The works of great composers tend to transcend, or to redefine, categories. Haydn and Mozart both wrote dozens of divertimentos, but in their hands the "entertainment" often reached great heights and depth. Mozart's trio for violin, viola, and cello, K. 563, for example, is called Divertimento, but by any definition it's serious music, a brilliant, beautiful, and profound piece. And like any great work of art or literature, it's effective and affecting on many levels at once.
For instrumental music of the late 1700s, the terms divertimento and serenade were virtually interchangeable. The original meaning of the word serenade, however, or serenata, in Italian, was "evening song" a song to be sung by a suitor under his beloved's window. Instrumental serenades dispensed with the requirement for love and windows, but the implication of outdoor performance in the evening, often in conjunction with meals or other festivities, remained.
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