Fourth
From Wikipedia, the free encyclopedia.

In music, see:

• Perfect fourth
• Augmented fourth or tritone

The subdominant, and the chord built on the subdominant, is often simply called the fourth as it is the fourth scale degree.

wiktionary:fourth

The original article can be found at: http://en.wikipedia.org/wiki/Fourth.
All text is available under the terms of the GNU Free Documentation License.