# What is the wavelength of middle "C" on a piano as it travels through air at standard temperature and pressure?

##### 1 Answer

Wavelength

#### Explanation:

Let's find out frequency of note Middle C to begin with.

A modern piano has 88 keys and is **tuned to twelve-tone equal temperament**.

It has its **49th key**, the fifth A, also called A4, tuned to a frequency of **440 Hz** (referred to as A440).

Due to twelve-tone equal interval, frequency of each successive key is derived by multiplying frequency (also called pitch) of lower key (or dividing pitch of higher key) by a factor of the **twelfth root of two**.

General expression which gives the frequency

Given note is Middle C, also called C4, is the 40th key. Inserting this value in general expression we obtain its pitch as

Remembering that

Taking speed of sound at STP (Temp