Metal chime tubes sway in a gentle breeze; the wind catcher occasionally swings into a tube, triggering a glowing chime ripple. A chime's pitch is set by its tube length, diameter, and wall thickness through bar/tube resonance physics — per Euler-Bernoulli beam theory, frequency scales roughly with thickness divided by length squared, so a small change in tube length shifts the note noticeably. Metal (often aluminum) tubes ring with long, sustained harmonic overtones because metal damps vibration slowly, while wood or bamboo chimes are more percussive and muted since wood absorbs energy much faster. Many tuned chime sets are deliberately cut to a pentatonic scale, since five-note scales avoid dissonant intervals and sound pleasant in almost any combination the wind produces. Drag to orbit, scroll to zoom.