Touch the string lightly directly above the fret wire — don't press down. Pluck elsewhere. The string splits into equal parts and only the matching partial rings. These are the ones that exist on a 24-fret neck.
Every plucked string vibrates in a sum of partials: the fundamental (1×), the octave (2×), the octave-plus-fifth (3×), and so on. Partial k has k−1 equally-spaced node points along the string where its motion is zero.
Resting your finger on any node silences every partial that doesn't also have a node there — only the target partial survives. Node position in frets: f = 12 · log₂(k / (k−m)) for node m of partial k.
The sounding pitch is k × f₀, where f₀ is the open string. Natural harmonics produce the harmonic series in just intonation — they don't match equal temperament. Partials 2, 3, 4, 6 are close (within a few cents); 5 is 14¢ flat; 7 is 31¢ flat (noticeably bluesy).
On any string, frets 5, 7, and 12 give you the three strongest harmonics — 2 octaves, octave+5th, and 1 octave above the open pitch. This is 95% of what you'll actually use live.
E-string pool: E3 · B3 · E2. A-string: A3 · E4 · A2. D-string: D4 · A4 · D3. G-string: G4 · D5 · G3.
Partial 3 has a second node at fret 19, partial 4 at fret 24. These often ring louder and clearer than their open-position counterparts — the string has more length-per-cycle above the pickup, so signal is cleaner.
Fret 19 on E = B3 (same pitch as fret-7 harmonic). Fret 24 on E = E3. Useful for chord-melody where you need the note near the pickup.
Rest index finger across fret 5 on both A and D strings. Pluck both. You get A3 + D4 — a perfect 4th, two octaves up. Same trick at fret 7 gives you E4 + A4, at fret 12 A2 + D3.
Try fret 5 on D + fret 7 on G: D4 + D5 — a pure octave voicing.
Fret any note with the left hand. Touch the string lightly with the right-hand index 12 frets higher, pluck with the thumb behind the index. Result: the fretted pitch one octave up, as a bell-like harmonic.
Works anywhere. Combine with hammer-ons/pull-offs to play melodies entirely in harmonics. Jaco and Victor Wooten both live here.
Ring fret-5 harmonic on low E (= E3, partial 4) and fret-7 harmonic on A (= E4, partial 3). In just intonation both are "E" but one octave apart — they beat if A is out. Adjust A until beating stops.
Repeat A-5 vs D-7, D-5 vs G-7. Caveat: this produces a 3:2 tempering between adjacent strings, which is slightly tight against equal temperament. Fine for solo bass; refine with a tuner for ensemble.
Between frets 2–3 (closer to 3) on any string. Silky, flat minor 7th. Doesn't line up with ET — don't try to play it in unison with a keyboard, but great for solo intros, ambient pads, or over static minor-seventh chords where it colors the ♭7 with just intonation.
Easiest node: fret ~2.7 on E = ≈D4 flat. Slide your finger until it speaks cleanly.