inharmonicity

[Newton Hunt]

Simply put, when the tension is increased (by changing the wire size)
the inharmonicity increases.  This can be proven using the formulas
posted earlier.

Inharmonicity (inh) is caused by the stiffness of the wire from it's
tension, it diameter and the fact that the wire is not hinged at the
terminal points.  Indeed, if the terminals were hinged there would be
almost no inharmonicity.  All stringed instruments have inh, albeit
very low in some, and no matter what the string is made of.  Some
instruments like zithers or autoharps have inh so low it it hard to
measure but it is there.

The only way to uncouple inh and tension is to change the speaking
length or to wrap the string with copper, iron or aluminum.

		Newton