Wolf tones require body modes that strongly rock the bridge, not just any resonance

Evidence

The wolf preys on the coincidence of string vibration frequencies and a poorly damped body vibration (an isolated body resonance). This much happens at other frequencies too, however, but these do not incite a wolf note. The wolf prefers coincidences with particular body vibrations that rock the bridge with large amplitude, as we will now discuss. (Some top plate deformations are better at rocking the bridge than others; a mode with a nodal line perpendicular to the bridge would do nicely, with one foot dipping down and the other thrusting up.) — Eric J. Heller, Why You Hear What You Hear- An…, 1798

Categorization

• XREF: The mechanism of energy exchange between string and bridge rocking resembles the impedance-matching and energy-transfer problems familiar from coupled-oscillator and matching-towers contexts in earlier chapters of this book.