n Japan, it’s an end-of-year tradition to sing “Ode to Joy,” the final movement of Beethoven’s Ninth Symphony. The song is so well-known in Japan that it’s known simply as daiku, literally “number nine.” In Osaka, a 10,000-person-strong “Number Nine Chorus” of amateur singers performs daiku every December, to thundering effect. While there are some professionals involved (the soloists and orchestra), the Number Nine Chorus is largely a community effort. And the sound of 10,000 singers, trained or untrained, is unbelievable.

In 2011, in the wake of the devastating earthquakes and tsunami in Japan, the Number Nine Chorus gave this performance. If you want the most dramatic part, skip to about 6:30, turn it up, and prepare to weep.

-from Mental Floss