Carillon strike the inside of the bells, allowing the performer on the bells, or "carillonneur/carillonist" to vary the intensity of the note according to the force applied to the key. Although unusual, real carillons have occasionally been fitted to theatre organs (instead of the metal bars or chimes more often used in simulation), such as the Christie organ installed at the Regal Cinema, Marble Arch, in London. A carillon-like instrument with fewer than 23 bells is called a chime. The carillon is the second heaviest of all extant musical instruments, only ranking behind the largest pipe organs. The heaviest carillon in
Brigham Young University Centennial Carillon Tower half-hour strikes are controlled by an automated system. Carillonneurs may also play the instrument by means of a keyboard located directly below the belfry, in a small room reached by a spiral staircase that ascends through the center of the tower. BYU is owned by The Church of Jesus Christ of Latter-day Saints, and its carillon is the only such instrument the church owns. LDS churches rarely feature bell towers, and the only temple to contain even a single bell is the Nauvoo Illinois Temple. Brigham Young University Centennial Carillon Tower The BYU Centennial Carillon is a carillon on the