It's startin' to look a lot like christmas

So, I play this game with my friends where one person taps out the beat of a christmas song with their hands and the other people have to guess the song. When the tapper reveals the song, they sing it out loud. I was revealing my song, Last Christmas I gave you my heart~ And the guessers started singing. Normal. Until we all start singing at max volume. The class was dead silent except for a couple whipers from the people beside us, so all anyone could hear was: LAST CHRISTMAS I GAVE YOU MY HEART, BUT THE VERY NEXT DAY YOU GAVE IT AWAY. THIS YEAR TO SAVE ME FROM TEARS I'LL GVE IT TO SOMEONE SPECIAL... It was really fun. Note we were doing this in the middle of lunch. And no teacher, not even one, complained about the noise. It was awesome!