The bass note does not always have to correspond to the root note of the chord, i.e. a C chord can have other bass notes under it besides the C root note. Common alternative bass notes are the third, fifth, seventh, etc. This has a profound effect on the structure of the song as the chord progression is changed.

Alternative bass notes are written after the chord. e.g. C/E is a C chord with an E bass note.

Chords with alternative bass notes are also known as slash chords because of the " / " symbol.

Following are some examples of common alternative bass notes.

Example 63a

The chord progression for this example is:

Notice how the actual chords would have simply been C to D over and over but the bass makes the progression climb.

Example 22d in the Rock section explains another use of alternate bass note which is a bass pedal where the bass note stays the same over a changing chord progression such as:

Dmin

Bb/D

C/D.