singalong

noun

1. A gathering of people who sing together

   “Thom Yorke’s onstage pronouncements became less abstract and more effusive, they played the songs the less committed audience members doubtless wanted to hear in the first place: Paranoid Android, Creep, Fake Plastic Trees and Karma Police. At the end of the latter, Yorke happily led an audience singalong.”

adj

1. (not-comparable)designed to allow or encourage the audience to sing along

   “ABBA had a talent for writing great singalong pop songs.”