This story was originally published Dec. 8.

There's a busker performing Christmas carols in downtown Calgary right now, but he doesn't sing or play the guitar.

Mike Holloway fills the Plus 15 with crystal clear whistles.

"Ever since I was a little boy, I always liked the sound of the whistle. I'm from Halifax originally, so you'd hear the train whistles," he told the Calgary Eyeopener.

Holloway will be tootling away until Dec. 18, raising money to buy Christmas toys for children staying at the Calgary Women's Emergency Shelter.

The 61-year-old has "groomed" his lips so he can whistle non-stop for two to three hours.

"I'd have to say it's a God-given ability because I couldn't train myself or teach myself this ... I can breathe through my nose, but my air passage actually blocks when I whistle. So no air comes out of my nose which gives me the ability to have full control over the pressure when I whistle it out."

"I move myself in different angles to get a different acoustic sound. So depending on the song I'm doing, I'll face a certain direction and get that tone that I need for people to hear and it just blows them away."

Holloway has been street performing for the last 15 years and was named Whistler of the Year in 2009 by the Country Gospel Music Association.

Mike Holloway, 61, says he's "groomed" his lips so that he can whistle non-stop for two to three hours. (Falice Chin/CBC)

With files from the CBC's Falice Chin and the Calgary Eyeopener