Which term would you use to describe a piece that is played cheerfully and briskly?

The term "Allegro" is used to describe music that is played cheerfully and briskly. In musical terminology, "Allegro" indicates a fast tempo, generally between 120 and 168 beats per minute, and often conveys a joyful character in the music. This term sets an energetic and lively mood, making it suitable for pieces that are intended to sound upbeat and spirited.

The other options refer to different qualities or moods in music. "Appassionato" translates to playing with passion and intensity, which is more about expressing deep emotion rather than maintaining a brisk pace. "Amabile" suggests a gentle or agreeable quality, typically associated with sweetness and tenderness, rather than a lively tempo. "Animato," while it does imply a spirited or animated character, doesn't specifically indicate the same brisk tempo that "Allegro" does. Thus, "Allegro" is the most appropriate term for describing a piece that is played cheerfully and briskly.