Encyclopedia > Perfect fourth

Article Content

Perfect fourth

The musical interval of a perfect fourth is the relationship between the first note (the root or tonic) and the fourth note in a major scale.

It can be produced by starting on a high note and playing the fourth below or by starting on a low note and playing the fourth above.

An "ideal" perfect fourth in just intonation corresponds to a pitch ratio of 3:4 or 1:1.333...

In an equal tempered tuning, a perfect fourth is equal to five semitones, a ratio of 1:2^5/12 or approximately 1:1.3348.

Compare with: perfect fifth

All Wikipedia text is available under the terms of the GNU Free Documentation License

Search Encyclopedia

Search over one million articles, find something about almost anything!

Featured Article

Kuru Kuru Kururin

... Kuru Kururin Kuru Kuru Kururin is a game for the Game Boy Advance. The player controls a slowly spinning stick and must get it through a series of mazes without touching ...