Instrument tuning relies on high harmonics because pitch changes there are easier to hear

Evidence

Musical tones, however, are rarely sinusoidal tones; they comprise many harmonic components and the frequency changes of these high-frequency harmonics can be more easily detected than frequency changes of the fundamental. Thus we usually listen to higher frequency harmonics when tuning a musical instrument. — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 1056

Categorization

• XREF: Explains a practical musical phenomenon (why players hear upper partials when tuning) through the psychoacoustic sensitivity curve — bridges the book’s models to real-world musicianship.