Learn the function of notes within a chord part 5

The last “box” to look at is the one for the 5th

In this “box”, we can have one of three notes, the b5 (or diminished 5th), the 5 (or perfect 5th) and the #5 (or Augmented 5th). When the chord has a perfect 5th, it is usually omitted from the chord name as it is the standard form. The Augmented 5th is mainly written as a “+” after the Root note, and occasionally we may see “aug”. The Diminished 5th requires slightly more explanation.

Any chord with a b5 is often referred to as diminished. I do not subscribe to that and often refer to it as a b5 instead. It is perfectly OK to belong to both camps as music theory is not law and is flexible to allow us to approach it from different viewpoints. Using A as the root note, we can have.

Diminished 7th chord written as A° (1       b3           b5           bb7)
Diminished Chord written as Adim (1       b3           b5)
The Half-Diminished Chord or m7b5 written as AØ or Am7b5 (1    b3           b5           b7)
Any extended chord with a b5 in it, written as A9b5, for example.

A special note on the Diminished 7th and the Augmented Chord – These chords have equal spacings between all the degrees of the chord and, as such, have a non-descript tonal centre. The augmented chord has a Major 3rd between each degree of the chord. The Diminished 7th has a Minor 3rd between each degree.

​Let us look at our five open chord shapes again.
​
As before original chord tones are in red.

​​For the D, we use the 3rd string as the box for the 5th of the chord, and the 5th can be moved down to create the b5 or #5. Giving us the Chords Ddim or D+

---

​For the A, we use the 4th string as the box for the 5th of the chord, and the 5th can be moved down to create the b5 or #5. Giving us the Chords Adim or A+

---

​For the E, we use the 5th string as the box for the 5th of the chord, and the 5th can be moved down to create the b5 or #5. We must mute the 5th on the 2nd string for this chord to sound correct. This gives us the Chords Edim or E+.

---

​For the C, we use the 1st or 6th string as the box for the 5th of the chord, and the 5th can be moved down to create the b5 or #5. We must mute the 5th on the 3rd string for this chord to sound correct. This gives us the Chords Cdim or C+.

---

​For the G, we use the 2nd string as the box for the 5th of the chord, and the 5th can be moved down to create the b5 or #5. We must mute the 5th on the 4th string for this chord to sound correct. This gives us the Chords Gdim or G+.

---

​​Next time we will fit all these together to allow us to create chords from there chord name