moodsetter

English

Etymology

From mood +‎ setter.

Noun

moodsetter (plural moodsetters)

1. A person, thing, or event that determines the emotional tone in a time and place.
   • 2011, Cheryl Charming, The Everything Cocktail Parties and Drinks Book, link:

     The third cocktail party essential, music, is a major moodsetter for your party.