The violin’s harmonics are phase-locked so their sum produces a traveling kink

Evidence

The Helmholtz mode of string oscillation is a remarkable discovery. Cooperative resonance between bow and string sets up the many harmonics working together. The phases of each mode are finely choreographed to produce a kink in the string. … The time dependence of the string shape is also shown, assuming one set of random phases. The shape of the string for random phases is still periodic in time— regaining its shape at time t again a time T later, where T is the period— but there is no kink capable of precise periodic initiation of sticking and slipping. — Eric J. Heller, Why You Hear What You Hear- An…, 1758