What is an augmented interval?

An augmented interval is defined as a major interval that has been raised by a half step. This means that when you take a major interval, typically consisting of a specific number of whole and half steps, and then increase its pitch by a half step, the result is termed "augmented." For example, if you have a major third interval (which spans four half steps), raising this interval by an additional half step will create an augmented third, which spans five half steps in total. Understanding this concept is essential for building and identifying chords, as well as for composition and analysis in music theory.

The other options describe different musical intervals: a perfect interval raised by a whole step results in an augmented interval, but it does not specifically represent the definition of an augmented interval. A major interval lowered by a half step describes a minor interval, while a minor interval lowered by a half step leads to a diminished interval. Each of these options indicates a different type of alteration to the original intervals and thus does not align with the definition of an augmented interval.