ST. PETERSBURG, Fla. (AP) — With eyes closed, you'd never know you were standing in the men's bathroom. It's not a likely place to hear such vibrant harmony — unless you're at Gibbs High School.

Fifteen students there meet twice a week during lunch in a small, two-stall restroom inside Building 5 to perform music they arrange themselves. And with more than 1.2 million total views of their videos on YouTube, it's clear the world is watching.

The idea for Men's Bathroom Choir was born last fall when Timofei Sennikov, 18, thought about the nice acoustics offered by the cinder block walls. He star...