Physical modeling
Don't record a string — model its physics. Karplus–Strong plucks a string out of noise.
Every method so far builds a sound from waves and filters. Physical modeling does something bolder: it simulates the physics of a real instrument. The most elegant example, Karplus–Strong, makes a startlingly real plucked string out of almost nothing.
A burst of noise is poured into a short delay whose output loops back through a filter — and rings like a string.
Here is the whole trick. A very short burst of noise — the finger plucking — is fed into a delay lineexactly one wavelength long. The delay's output is looped back into its own input, so the burst circulates round and round, and its pitch is set by the delay's length. Each lap it passes through a gentle lowpass filter — the damping — that shaves off a little high end, so the tone mellows as it fades, just like a real string.
No sample and no wavetable — just noise, a delay and a filter, modelling how a string actually behaves.