songfest

From song +‎ -fest.

songfest (plural songfests)

1. An event, often informal, where people sing together for the pleasure of it.
   • 1966 March, Thomas Pynchon, chapter 4, in The Crying of Lot 49, New York, N.Y.: Bantam Books, published November 1976, →ISBN, page 59:

     The routine business took an hour; for another hour the shareholders and proxies and company officers held a Yoyodyne songfest.

• snogfest