Well, in the previous article, we talked about the chord of second degree (II7). Now we will talk about a chord that is closely connected to it: the half diminished sharp chord of fourth degree #IVm7(b5).

Where to use the chord #IVm7 (b5)?

This kind of chord can act like a passing chord between IV and V degrees.

Before everything, let’s name the things to not being so abstract: you can suppose that we are in the C tonality. IV and V degrees, therefore, will be F and G chords. And the chord #IVm7(b5) will be the F#m7(b5) chord.

Back to the subject we proposed, the F#m7(b5) chord can be used as a passing chord between F and G chords. It is possible to notice that one of the reasons for this being possible is the chromatic effect which is associated, because the bass note is going chromatically from F to G. But why does the chord need to be half diminished (m7b5)? Pay attention in this:

  • Notes of #m7(b5) chord:   F#, A, C, E
  • Notes of D7 chord:  D, F#, A, C

As you can see, these chords have 3 notes in common; and besides that, the tritone from D7 chord (created by F# and C notes) also is present in the F#m7(b5) chord. Moral of the story: one can have the function of the other!

Nice, but what does it mean in practice?

Well, the D7 chord is the dominant of G, isn’t it? So then, playing D7 before G would be a cadence “V – I” (perfect cadence), while playing F#m7(b5) chord before G would have the same purpose, being a cadence “VII – I” (imperfect cadence).

Very well, so it is explained! The F#m7(b5) chord can be used between the F and G chords due the chromatic effect and the formation of a cadence “VII – I”. Now you are able to use this resource whenever you want.

Observation: if the F#m7(b5) chord is followed by B7, it is acting like II degree of a progression II – V – I to E minor, then the previous thought is not applied, because the purpose is another one.

Before finishing the subject, just notice that D7 is the second major degree (II7) of C; then don’t be surprised if, “by accident” you see the #IVm7(b5) chord replacing the second major degree (due the fact that they are really similar). The utilization of #IVm7(b5) is not restricted to stay only between the IV and V degrees; remember that everything is possible when the subject is music.

It is important to notice that, as being a strange chord to the tonality, the #IVm7(b5) chord will not always sound well. It is needed being aware of the produced effect. As much practice you have in the use of this chord, faster you will know how to identify it and also how to fit it in the songs that don’t have it.

We tried to pass here in the website the fundamental concepts to avoid doubts and to awaken ideas in the functional harmony aspect. The real application of these concepts, however, will be connected to the melody and the good taste of the composer.

Go to: Improvising with outside notes

Back to: Module 11