Tubular Bells

A bell-like sound can be obtained by tuned metal tubes. They are commonly referred to as bells or chimes. A similar instrument is constructed of metal bars.

The set of hollow vertical pipes is suspended at the top of the pipes by thin wire. Each pipe is struck with hammers on the top part of the chime. The three lowest modes of vibration of a chime tube have frequencies with ratios 2:3:4. The ear perceives this as the pitch one octave below the fundamental by the missing fundamental effect. Other overtones depart from this approximate linear set of harmonics and help give the chime its unique sound. There are end plugs which are said to add to the sustain of the tone and to damp out high harmonics. The end plug helps to lower the frequencies of the first few modes, but has little effect on higher modes.