The sound of bells will come from Washington National Cathedral nearly all day tomorrow in a glorious display of carillon music followed by a 31/2-hour marathon of rope-pulled bell-ringing.

In the morning, between the early service at 8 and main service at 11, carillonneur Edward M. Nassor will play Easter hymns and other sacred music on the 53-bell Kibbey carillon, at 64 tons one of the heaviest carillons in the world.

After the 11 o'clock service, the Washington Ringing Society will attempt a "full peal," in which the 10 peal bells are rung in a mathematical sequence that calls for more than 5,000 variations in the order in which they are played. The process, called change ringing, will continue well into the afternoon, until about 4 p.m.

The carillon consists of stationary bells played through a clavier, or keyboard, located in a small room below the massive bell system. The carilloneur plays melodies by pushing the batons of the clavier and pressing pedals with his feet. A system of wires connects the keyboard to clappers inside the bells.

The peal bells, located above the carillon in the cathedral's central tower, are operated by ringers who pull long ropes attached to circular frames holding the bells, which weigh from 608 to 3,588 pounds. Each ring takes about two seconds, so peal bells are not used to play melodies.

The bells are rung regularly by members of the ringing society and students at National Cathedral School. But only on special occasions such as Easter and Christmas do ringers attempt a full peal. Completing a peal is a major achievement, requiring ringers to work without a break and without written instructions. Instead, they follow memorized patterns and cues from a ringer who also acts as a conductor and works from memory.

If tomorrow's peal is successful, society members Theresa Rice and Meredith Morris will have rung "full circle," meaning they will have participated in successful peals on each of the 10 bells. Only three people have accomplished this feat at the cathedral, and Rice and Morris would be the first women to do so.

To view a photo gallery with sounds of the carillon and peal bells and to hear interviews with carillonneur Edward M. Nassor and bell ringer Theresa Rice, go to www.washingtonpost.com/metro.

Theresa Rice, a Washington Ringing Society member, works as one of 10 "change ringers," in a tradition that dates to 17th-century England.Tess Veuthey, from left, Alex Evans and Maggie Byrne, all 17-year-old students at the National Cathedral School, ring the rope-pulled bells at National Cathedral. Above, Cathedral carillonneur Edward M. Nassor operates the keyboard of the 53-bell Kibbey carillon, in a small room beneath 64 tons of bells. Steeple keeper Ed Donnen conducts a safety check of the rope-pulled bells, which will be used for a "full peal" tomorrow. A team of 10 will ring the bells in ever-changing sequences.