A guitar can look flawless yet behave unpredictably in the moments that matter. You tune carefully, play a few expressive bends, and the pitch returns a little “not quite right.” Open chords can sound slightly sharp, and a capo may make familiar shapes feel tense and unforgiving. These aren’t a dramatic failure, which is why they’re so annoying: the instrument works, but it doesn’t settle. Most of that instability begins at the first contact point, guiding each string toward the first fret, where friction, slot geometry, and pressure decide whether the string glides or grips.