Instruments and acoustics

Guitar fret positions (12th root of 2)

Guitar frets are a geometric series, and the saddle must still be moved back to play in tune

This drawing comes from one YAML file. No shape was moved by hand.

Notes in the source (in Japanese)

フレットは等間隔ではない。

1 フレットごとに 1 / 2^(1/12) 倍。だから 12 フレットでちょうど半分になる。式は n 番の位置＝ S ×（1 − 2^(−n/12)）。

そして 理論どおりに作っても音は合わない ——押さえると弦が伸びて音程が上がるので、サドルを後ろへずらす（弦ごとに違う）。

同じ題材で、見本 310 もある。 こちらは寸法（12√2 と実際の位置）、310 は「なぜ等分ではなく比なのか」を扱う。

Source (YAML)

examples/gallery/204-ギターのフレット位置.zumen.yaml

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