Why approaching from below helps
String motion must pass through the tuning-post wraps, nut slot, and sometimes a string tree. Approaching while tightening keeps these contact points loaded in the same direction used during playing.
What happens after overshooting
Simply backing down a tiny amount can leave stored tension on one side of a binding nut. The tuner may look correct until a bend or chord suddenly releases that tension and changes pitch.
Do not confuse direction with peg rotation
The physical direction a tuning key turns depends on headstock layout and string installation. Watch the tuner and listen: tightening raises pitch and loosening lowers it.
Step-by-step check
- If the note is flat, tighten slowly toward the center.
- If it becomes sharp, loosen below the target.
- Pluck again and approach upward.
- Stretch or bend the string lightly to test stability.
- Retune upward once more if the pitch changed.
Reliable tuning habits
Work with one string at a time, use a moderate and repeatable picking attack, and let the initial pitch settle briefly. Make the final adjustment by approaching the target from below so slack is taken out of the tuning post and nut. After all six strings are close, repeat the entire pass because every tension change can slightly affect the other strings.