ORCHESTRAL BELLS

 

Australian Bell has produced a two chromatic octave set of harmonic bells for the Melbourne Symphony Orchestra. These sets of bells have not yet been seen or heard publically, but some were previewed in the premier performance of Ros Edward's Symphony No. 5 by the MSO at the Melbourne Town Hall in May 2000.

The largest bell is pitched at G3 and is over 1/2 a metre in diameter and weighs about 35kg. The 25 bells are arranged in 2 semi-circular frames that are a little over 2 metres each in diameter. The bell set contains bells of three distinct profiles. The higher the pitched bells have narrower profiles in order to reduce the circumference at the rim and so raise the pitch without reducing the size and loudness of the bells. The narrower profiles have fewer partials tuned harmonically (as few as 4) but this is not a concern acoustically as fewer partials have sustained resonances in high pitched bells.

	Orchestral bells in frames (low octave on left)
	Testing the tuning of the orchestral bells and their sound in relation to the tubular bells and piano.

The orchestral bells were made by casting lugs that were cut to the required by profile on a computer controlled lathe. The bell was then fine tuned by hand on a vertical or horizontal laithes depending on size.

Cast lugs	Computer lathe at North Central Engineering	Large orchestral bell being fine tuned on the vertical lathe