Wind Chimes can be made of materials other than metal or wood and in shapes other than tubes or rods. Other wind chimes materials include glass, bamboo, shell, stone, earthenware, stoneware, beads, keys and porcelain. More exotic items, such as silverware or cookie cutters, can also be recycled to create wind chimes. The selected material can have a large effect on the sound a wind chime produces. The sounds produced by recycling objects such as these are not tunable to specific notes and range from pleasant tinkling to dull thuds. The sounds produced by properly sized wind chime tubes are tunable to notes. As aluminum is the common metal with the lowest internal damping, wind chimes are often made from aluminum to achieve the longest and loudest sounding chime.
The tone depends on factors such as the material, the exact alloy, heat treatment, and whether a solid cylinder or a tube is used. If a tube is used, the wall thickness also affects the tone. Tone may also depend on the hanging method. The tone quality also depends on the material of the object that is used to hit the chimes.
With clay wind chimes, the higher the final firing temperature, the brighter and more ringing the resulting tone. Earthenware clay fired at lower temperatures produces a duller sound than stoneware clay fired at higher temperatures. Stoneware wind chimes are also more durable and able to resist stronger winds without suffering chipping or damage.
Chimes produce inharmonic (as opposed to harmonic) spectra, although if they are hung at about 2/9 of their length (22.4%), some of the higher partials are damped and the fundamental rings the loudest. This is common practice in high-quality wind chimes, which are also usually hung so the centre ball strikes the centre of the wind chime's length, also resulting in the loudest sounding fundamental. Frequency is determined by the length, width, thickness, and material. There are formulas that help predict the proper length to achieve a particular note, though a bit of fine tuning is often needed.
Most chimes employ pentatonic or tetratonic scales as the basis for the pitches of their individual chimes as opposed to the traditional western heptatonic scale. This is largely due to the fact that these scales inherently contain fewer dissonant intervals, and therefore sound more pleasant to the average listener when notes are struck at random.
In instruments such as organ pipes, the pitch is determined primarily by the length of the air column, because it is the resonance of the air column that generates the sound. The pipe material helps determine the "timbre" or "voice" of the pipe, but the air column determines the pitch. In a wind chime, the vibrations of the pipe itself radiate the sound after being struck, so the air column has little to do with the pitch being produced.
Sound can be produced when the tubes or rods come in contact with a suspended central clapper in the form of a ball or horizontal disk, or with each other.
Wind chimes may be used to observe changes in wind direction, depending on where they are hung when they commence to sound.