# Fundamental frequency

### From AudioLexic

The **fundamental tone**, often referred to simply as the **fundamental** and abbreviated **f _{o}**, is the lowest frequency in a harmonic series.

The **fundamental frequency** (also called a **natural frequency**) of a periodic signal is the inverse of the pitch period length. The pitch period is, in turn, the smallest repeating unit of a signal. One pitch period thus describes the periodic signal completely. The significance of defining the pitch period as the *smallest* repeating unit can be appreciated by noting that two or more concatenated pitch periods form a repeating pattern in the signal. However, the concatenated signal unit obviously contains redundant information.

A 'fundamental bass' is the root note, or lowest note or pitch in a chord or sonority when that chord is in root position or normal form.

In terms of a superposition of sinusoids (for example, fourier series), the fundamental frequency is the lowest frequency sinusoidal in the sum.

## [edit] See also

This article was started using a Wikipedia frequency article |