It takes 10 people more than three hours to do a full peal on the bells in the tower of the Washington National Cathedral - and the bellringers will try to do two full peals this weekend, in honor of the 50th anniversary of the dedication of the bells.
The ringers did the first peal Saturday afternoon. Another full peal is set to begin Memorial Day at noon.
The ten bells weigh from 608 to 3,588 pounds apiece. Each ringer pulls on a rope attached to one of the bells. In order to protect their hearing, they work from a room in a separate room beneath the bells.
Here's what a quarter peal sounds like - from a YouTube video from last year: