# Difference between revisions of "Half step"

From Audacity Wiki

m (the correct formula for an equal-temperament half step) |
m (fix link) |
||

Line 9: | Line 9: | ||

(Just like an octave, a half-step interval is a ratio obtained through division, not a difference obtained through subtraction. One octave above 440 Hz is 880 Hz, while one octave below is 220 Hz. The size of the octaves in Hz is different, but the ratio is the same.) | (Just like an octave, a half-step interval is a ratio obtained through division, not a difference obtained through subtraction. One octave above 440 Hz is 880 Hz, while one octave below is 220 Hz. The size of the octaves in Hz is different, but the ratio is the same.) | ||

− | Different "tempereraments" actually have slightly different half-steps. See the Wikipedia article [http://en.wikipedia.org/wiki/ | + | Different "tempereraments" actually have slightly different half-steps. See the Wikipedia article [http://en.wikipedia.org/wiki/Semitone Semitone] for details. |

## Revision as of 16:22, 5 April 2006

A **half step** is one twelfth of an octave.

### Formula for a Half Step

Since an octactave has a frequency ratio of 2, a half-step has a frequency of 2^(1/12), or approximately 1.0595.

For example, if the note A has a frequency of 440 Hz, then one half-step up is 440*1.0595 = 466.2 Hz. One half-step down is 440/1.0595 = 415.3 Hz.

(Just like an octave, a half-step interval is a ratio obtained through division, not a difference obtained through subtraction. One octave above 440 Hz is 880 Hz, while one octave below is 220 Hz. The size of the octaves in Hz is different, but the ratio is the same.)

Different "tempereraments" actually have slightly different half-steps. See the Wikipedia article Semitone for details.