Whereas the existing Westminster Carillons consisting of four permutations of four pitches, Jaeger-LeCoultre’s Grande Sonnerie strikes six different permutations at the full hour (and one, two and three at each quarter).
The striking modes can be changed with the higher pusher at 4 o’clock. It sets the musical mechanism to “Grande Sonnerie”, “Petite sonnerie” or “Silence”.
In the petite sonnerie mode, the timepiece strikes three permutations at the full hours with four Westminster Chimes, and switches to the silence mode after six hours of activation.
The minute repeater function can be activated on request by pushing the button situated at the centre of the crown (only available when silence mode is selected). Still using the four gongs; it strikes the time using a series of four tones. Firstly the hours are struck by the low-note gong, then the quarters with the corresponding permutations series (one, two and three) and finally the minutes elapsed since the last quarter by the high-note gong.