Inharmonicity of Sounds from Electric Guitars: Physical Flaw or Musical Asset?
Hugo Fastl, Florian Völk · 2008
Because of bending waves, strings of electric guitars produce (slightly) inharmonic spectra. One aim of the study was to find out- also in view of synthesized musical instruments- whether sounds of electric guitars should preferably produce strictly harmonic or slightly inharmonic spectra. Inharmonicities of typical sounds from electric guitars were analyzed and studied in psychoacoustic experiments. Strictly harmonic as well as slightly inharmonic spectra were realized and evaluated with respect to audibility of beats, possible differences in pitch height, and overall preference. Strictly harmonic as well as slightly inharmonic spectra produce essentially the same pitch height. Depending on the magnitude of the inharmonicity, beats are clearly audible. Low, wound strings (e.g. E2, A2) usually produce larger inharmonicities than high strings (e.g. E4), and hence beats of low notes are easily detected. The inharmonicity increases with the diameter of the respective string's kernel. Therefore, an unwound G3 string can show larger inharmonicity and more prominent beats than a wound D3 string. In a musical context, i.e. when playing short melodies with synthesized strictly harmonic versus slightly inharmonic string sounds, the latter are somewhat preferred, in particular by players of string instruments. The slight inharmonicity of sounds from electric guitars is not a physical flaw which should be avoided by synthesizing perfectly harmonic sounds, but can be regarded as a musical asset. I.