The pound of a fist against a wooden peg creates a tug on a thin steel cable that attaches to a bell - not just any bell, but one of 52 cast bells located in the BYU Carillon Bell Tower.

BYU's signature sound comes from the sounding bell tower. Each hour the tower chimes the famous "Come, Come ye Saints," followed by a "dong" marking the hour. Occasionally students are privileged to hear Don Cook, the University carillon player, play LDS hymns, classics or movie themes. Since the end of August, however, the bells have only chimed the hour tune because of a maintenance upgrade to the bell tower's playing mechanism.

Don Swem, BYU's bell tower maintenance man from Belmont, Mich., nicknamed the "Guru of the Bells" by BYU employees, is currently replacing felts that surround the keys of the instrument, cables that attach the bells to the keys and other devices on the playing mechanism, which have been worn out by weather and use. The bells will resume their familiar chiming after devotionals at the end of this month.

"The last time the keyboard received an upgrade was in 1993," Cook said.

Even though the maintenance upgrade seems simple, the details take a while to get everything right, Swem said. At the beginning of the project, the bells were silenced and Swem programmed the hourly "Come, Come Ye Saints" chime. The first couple of days played the hourly rendition with abnormal rhythm and no rests, Cook said.

To play the bells, Cook must make a vertical hike of 90 feet up 110 stairs in the shaft of the bell tower. Once Cook reaches the top of the spiral staircase, he enters a room and climbs a smaller, more vertical staircase, one that resembles a ladder, into another room that houses the organ-like keyboard.

Brian Mathias from Minneapolis, Minn., a junior majoring in organ performance, said that he enjoys the experience of playing the bells.

When Cook plays he opens up hatches that lead directly to the bells or turns on the PA system to listen so that he can hear what he plays.

Swem's wife, Jeanne, said her husband was going deaf because he was always so close to the bells when they sound.

The bell tower was constructed in 1975 and dedicated by President Kimball. Although Swem makes minor changes each year, the 52 cast bells are original.