Octo Roma Grande Sonnerie Tourbillon

When developing its new chiming watches – this model, the Octo Roma Carillon Tourbillon and the Octo Finissimo Minute Repeater Carbon -, Bulgari enlisted the services of the Italian-Swiss conductor Lorenzo Viotti, who is the chief conductor of the Netherlands Philharmonic Orchestra. The sequence of chimes for this Octo Roma Grande Sonnerie Tourbillon is based on a tritone: a musical interval of three adjacent whole tones or six semitones. A chromatic scale contains 12 tritones which are classified as augmented fourths or diminished fifths. By composing a melody around the tritone, once referred to as the "devil's interval", Viotti introduces tension and dissonance to the watch’s chimes. 

The 45mm Octo Roma case is fashioned in platinum and frames an openworked dial. It houses the manual-winding BVV800 movement which beats at 21,600 vibrations/hour. Grande and petite sonneries are sounded on four gongs, completed by a minute repeater and a tourbillon regulator at 10 o’clock. Power reserve runs to 72 hours.