Rainbow Tower Rainbow Tower The Rainbow Tower is a tower located at the Rainbow Plaza Canada–US border station of the Rainbow Bridge in Niagara Falls, Ontario, Canada. Construction on the tower was completed in 1947. The tower, part of the Canadian plaza of the bridge, was designed by Canadian architect William Lyon Somerville. The Rainbow Tower houses a carillon—a musical instrument consisting of a baton keyboard that controls a series of bells. The Rainbow Carillon is sounded three times a day, 365 days a year. It features 55 bells with a total weight of over 43 tons. The instrument is controlled via
A (musical note) the pitch standard. The number designates the frequency in hertz. A lower number equals a lower pitch. By an international treaty signed in 1939, modern pitch is standardized at A-440. However, tuning has varied over time, geographical region, or instrument maker. In 17th-century Europe, tunings ranged from about A-374 to A-403, approximately two to three semitones below A-440. Historical examples exist of instruments, tuning forks, or standards ranging from A-309 to A-455.3, a difference of almost six semitones. Although the official standard today is A-440, some orchestral groups and chamber groups prefer to tune a little higher, at A-442 or