As it happens, pianos are deliberately tuned slightly flat in the bass and slightly sharp in the treble, to compensate for the inharmonicity of vibrating string

As it happens, pianos are deliberately tuned slightly flat in the bass and slightly sharp in the treble, to compensate for the inharmonicity of vibrating strings. https://en.wikipedia.org/wiki/Stretched_tuning https://en.wikipedia.org/wiki/Stretched_tuning