If you happen to be out someplace like Portland's Director Park, don't be alarmed. The men with the handlebar mustaches are professionals.
Today marks the closing of the Barbershop Harmony Society's International convention. April Baer reports hundreds of singers have invaded Portland for the event.
Quartets and choruses travelled from as far as Tokyo and Australia - and some closer spots.
"I'm Ed Novak," said one of the taller men in the crowd. "I live in Clarkston Washington, and I have a place in Oregon, over in Wallowa County. I started with lead and now I'm getting older, my voice is changing to bass. I went up to tenor, because I have a falsetto voice."
Novak says the quartets are doing aggressive outreach to show people you don't have to read music or know theory to enjoy the form.
"If you can sing in the shower, in tune, then you qualify."
None of the Oregon quartets progressed to the top rounds of competition. But Salem's Senate-Aires men's chorus placed fifth overall.
This story originally appeared on Oregon Public Broadcasting.