Gong Keyboard

Displacement of the last gong struck, from its live mode amplitudes (exaggerated, motion slowed). ● mallet, ■ microphones, - - the heavy axis. A soft strike shows one ring pattern; a hard one breaks into fine, restless detail.

A hard strike starts with a few lines; within a fraction of a second the space between them fills up to the top: the energy cascade.

The markers are the plate's modes, brighter where the mallet excites them; gold is the strike tone. A soft strike sounds them alone, a hard one fills the gaps between them.

Energy in octave bands of the struck gong's modes, relative to its pitch (top), and the strike tone's pitch (bottom): it falls as a flat gong rings down, rises for a dome.