What is a C(Maj)/F Chord?

I had seen chords in sheet music that looked like fractions. They were chords like C(Maj)/F or A(Maj)/G. It was not until I watched someone play an arrangement on the piano that the role of a fractional chord finally made sense to me. I could hear a whole new type of energy that did not exist when I simply played the literal chords in the chord charts. These alternate variations of a chord seemed to make chords to pop out into three dimensions like a 3-D picture!

The fractional chords are known as chords played over an Alternate Bass. They work to change the shade of the chord. One way to imagine it would be to think of a color and then consider what would happen if you increased the intensity of red in the color. As you increase the intensity of red, the original color would change into a different shade.

In the same way the following chord progression is an example of changing the intensity of the bass by stepping up the bass while holding the chord constant.

Example:
C(Maj)/C, C(Maj)/D, C(Maj)/E, C(Maj)/F, C(Maj)/G, C(Maj)/A, C(Maj)/B, C(Maj).

To play this progression you would hold the C(Maj) chord constant with the right hand above middle C. Then as you play the C(Maj) chord over and over in a loop you walk the bass up ascending from C one octave below middle C up to middle C.

As you do this notice how the C(Maj) chord does not sound like an ordinary C(Maj) chord when the bass is D, E, F, G, A, and B. These alternate shades of C(Maj) are used often in popular music. They are most likely the chords you were reaching for in the past but could not find in the chord charts by playing the literal chord chart alone.

One of my favorite fractional chord progressions is the following sequence:

G(Maj), A(Maj)/G, A(Min)/G, G(Maj) - This chord progression has a feeling of lift or flight.

You can explore fractional chords easily by slowly playing a scale under any chord. As you do you will be creating all possible fractional chords that exist within the scale. The scale that you play under the chord should start and end with the root of the chord. For example, if you explore Alternate Bass for a G(Maj) chord you would play scales that start and end with G in your left hand below middle C as you play the G(Maj) above middle C with your right hand. This will exponentially increase the number of chord colors you can create and add a new dimension to your chord progressions!