Music Theory for the 21st-Century Classroom

Common in popular music are “sus” chords, with “sus” being a shortening of “suspended,” a term we will study in the chapter on non-chord tones.

The two basic sus chords are the sus4 and sus2 chords. In the sus4 chord (also labeled simply as “sus”), a perfect 4th replaces the 3rd of the chord. In the sus2 chord (sometimes called “sus9”), a major 2nd replaces the 3rd of the chord. Both of these sus chords have a perfect 5th from the root to the fifth.

Here is a musical example with a sus4 chord.

Here is a musical example with a sus2 chord.

We will not invert sus chords in this text. In a later chapter, there is a section on more sophisticated sus chords like \(\left.\text{C}^{9}\text{sus}\right.\) and \(\left.\text{C}^{7}\text{sus}\left(\text{♭9}\right)\right.\).