YORK COUNTY, Pa. (WHTM) — Christmas is less than a week away, which means the York Factory Whistle is getting ready for its annual Christmas Concert.

Christmas carols played with the whistle have been a holiday tradition since 1955.

Donald Ryan took over the role after his father. On Saturday, he practiced for the event with his son. Ryan uses a handmade measuring stick to hit the notes.

Another person holds the whistle valve open while crews outside use a generator to produce enough air for a 20-minute concert that can be heard up to 10 miles away.

“It is not a musical instrument, it is a factory whistle. To be able to get music out of a non-musical instrument is something unique in itself,” Ryan said.

The annual concert begins at 12:15 on Christmas morning.