Guitar Tuner

Play one string at a time, reasonably close to the mic, and mute the others with your palm — the detector locks onto the strongest pitch, and two ringing strings confuse any tuner. Let the note ring rather than re-plucking rapidly; the first half-second of a pluck is pitch-unstable (strings start slightly sharp). For electric guitar, tune unplugged or with a clean tone: distortion adds harmonics that can pull the reading toward an overtone.

A cent is 1/100 of a semitone — the needle's ±50 range spans a quarter-tone each way. Within ±5 cents (the green zone) is in tune for all practical purposes: trained ears struggle to hear smaller errors in context, and a guitar's own intonation varies more than that up the neck. Chasing the needle to exactly 0 is mostly fighting your own pluck-to-pluck variation — get green, hold it half a second, move on.

String tension seats against the tuning peg's winding and the nut differently depending on direction: tuning up leaves the string pulled taut against the mechanism, while tuning down leaves slack that works itself out as you play — which is why a string tuned downward drifts flat within minutes. If you overshoot sharp, don't ease back down: drop clearly below the target and come back up. This one habit fixes most 'my guitar won't stay in tune' complaints.

Octave errors — the classic pitch-detection failure. A low E2 at 82 Hz has strong harmonics at 165 and 247 Hz, and if the fundamental is weak (small phone mic, thin strings, light pluck) a detector can lock onto a harmonic instead. This tuner's algorithm specifically favors the fundamental, but physics wins sometimes: pluck the low strings firmly near the neck (which emphasizes the fundamental) and give the mic a second to settle.