Definition of "capriccio"

Will this Capricio hold in thee, art ſure?

c. 1604–1605 (date written), William Shakespeare, “All’s Well, that Ends Well”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, [Act II, scene iii], page 239, column 2

If any Man for that reaſon has an Inclination to divert himſelf, and Sail with me round the Globe, to ſuperviſe almoſt all the Conditions of Humane Life, without being infected with the Vanities, and Vices that attend such a Whimſical Perambulation; let him follow me, who am going to Relate it in a Stile, and Language, proper to the Variety of the Subject: For as the Caprichio came Naturally into my Pericranium, I am reſolv’d to purſue it through Thick and Thin, to enlarge my Capacity for a Man of Buſineſs.

1700, Tom Brown, Amusements Serious and Comical, calculated for the Meridian of London, page 10

Above the drawing-room fireplace there was a painting by Guardi, a capriccio of Venice in a gilt rococo frame […]

2004, Alan Hollinghurst, The Line of Beauty […], 1st US edition, New York, N.Y.: Bloomsbury Publishing

The stillness returned, save for the little voices of the night—the owl's recitative, the capriccio of the crickets, the concerto of the frogs in the grass.

1909, O. Henry, “The Renaissance at Charleroi”, in Roads of Destiny‎