Carillon

bronze bells tuned partial by partial by finite elements, struck by iron clappers; the note you hear, the strike note, is a virtual pitch
MIDI off audio off

The bell C4: nominal

Left: the bell cut through its axis, to scale, with the chosen partial’s shape (exaggerated, slowed down); dashed: its nodal circles, ● the clapper at the strike height. Right: seen from below, the lip’s 2m lobes and nodal meridians, the doublet’s two axes (heavy side ━), the clapper’s strike point ▲ and the listener ◆. Below: that partial’s level as you hear it over the last 8 s; an uneven bell makes it beat. Pick a partial in the table.

Partials of C4

The strike note

Stems: the bell’s partials as you hear them now (live after a strike; before, as the model predicts). Curve: the pitch strength of subharmonic summation, each partial counted as the 1st, 2nd, 3rd … harmonic of every candidate pitch. Its peak, the strike note (red), sits an octave below the nominal, where the nominal, superquint and octave nominal (near 2 : 3 : 4) agree, whether or not a partial is there.

Spectrum

live output · markers: the bell’s partials (gold), the strike note (red)
The upper partials of a bell die fast, the hum lasts longest. From far away, air absorption takes the top off first.

Spectrogram

live output · ticks: the spectrum's markers
The upper partials vanish within moments while the hum, the lowest line, rings on and on; from further away the top goes sooner still.