12 October 2026 · Built with Claude
The wolf
Most cellos have one note that won't sit still. Near it, the string and the wooden body ring at almost the same pitch, pull against each other, and split into two pitches a few hertz apart. You hear the gap as a growl. Press and hold the fingerboard to bow; slide to change the note.
Keyboard: arrow keys move the finger, hold Space to bow.
Notes
The wolf is two resonators coupled together: the string, and the body's strongest low resonance. Far from the body's pitch, the string has the note to itself. Close to it, neither wins, and the note becomes two pitches that beat against each other, a few times a second. Cellists press harder into it, play it fast with less vibrato, or clamp a small weight, an eliminator, onto the string behind the bridge. That moves the body's pitch a little and soaks up some of the energy.
The site's mark is a wolf-tone trace drawn in pixel columns; this is where it comes from. The model is two coupled oscillators, not a recording, so it's a sketch of the physics rather than a particular cello.