Sharp Fifth (Augmented) Chords

In the last session we talked about “flat-fifth” chord where the 5^th of a chord is lowered. So this time, in reverse, the topic is to raise the 5^th of a chord.

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Either major or minor chords can have its 5^th altered. However, there is a difference in their significance. In the case of the flat-fifth, the “minor flat-fifth” was more crucial, whereas in the case of the raised fifth, conversely, the major becomes more important. Therefore in this article, I’ll treat only the major chord version.

1. The Sharp Fifth Chord

The chord name and the chord symbol is very simple: A major chord with its 5^th raised is called a Sharp Fifth chord and is symbolized by “^(♯5)” or “⁽⁺⁵⁾“.

The interval between Rt and the raised 5^th is now “augmented 5th“. So the chord is also called an Augmented chord.

While a minor flat-fifth chord can be constructed without any accidentals if rooted on VII of the key, sharp-fifth chords necessitates accidentals on some of the chord tones, therefore need a bit of care.

Seventh Chord Versions

If you apply sharp-fifth alteration to sevenths chords, the naming system is nothing different. Just simply place the symbol “(+5)” on the right shoulder.

For the minor flat-fifth, it was mentioned that it’s usually used as a seventh chord. However, in the case of the sharp fifth, if you desire a simple sound, a triad may be preferred, while for a more complex resonance, a seventh chord can be chosen. Each has its merits and is useful.

2. I, V, IV and Sharp Fifth

The most basic usage of the sharp-fifth is to transform the major chords I, V, and IV of the key.

It preserves the original Rt and 3^rd so it’s relatively easy to grasp how they sound like.

I⁽⁺⁵⁾

I⁽⁺⁵⁾ is typically inserted between I and IV.

See how the top notes move smoothly by half-step! It works like “glue” between the two chords. The sonority of so♯ is very much foreign to the key and the augmented fifth interval, do–so♯, also feels unstable, therefore the chord creates a strong musical tension, which should be resolved in the chord following. Other than IV, going to VI_m or going back again to I works as a good resolution.

V⁽⁺⁵⁾

Following the exact same principle, the V⁽⁺⁵⁾ chord is inserted between V and I.

(Or you can substitute V with V⁽⁺⁵⁾, like IV→V⁽⁺⁵⁾→I.)

Example

“Bremen” by Yorushika, a Japanese rock band, starts with a loop of jazzy 6-2-5-1 progression. But on the fourth loop, V is changed to V⁽⁺⁵⁾. You can clearly hear the twisted sound since the alteration is further emphasized by a vocal singing the very altered note, re♯.

Re♯ has a strong tendency upward, so here the melody moves re♯→mi to release its musical tension.

IV⁽⁺⁵⁾

IV is different in that it doesn’t have a good place to reach by 5_▼ (it will be the unstable VII chord). So if the sharp-five is applied, the chord to come next will be V or II_m.

In either case, the tendency of do♯ is resolved in an ideal way, the half-step ascending motion.

Example

“Morgen!” by R. Strauss is a beautiful is a beautiful piece in G major key. Watch the 3rd bar where the left hand involves a sharp on G! The chord here is CΔ7⁽⁺⁵⁾→Am/C, analyzed as IV_Δ7⁽⁺⁵⁾→II_m/IV.

How much the subtle dissonance of just one note created by the sharp-fifth contributes to the beauty of music! Let’s compare it with a normal major seventh chord version.

Simplified Version : CΔ7

Original Version : CΔ7⁽⁺⁵⁾

Oh~~~~~~~~~~ God is in the details. In this way, sharp-fifth chords work as a subtle “poison” that brings stimulation to a song.

3. III, VI and Sharp Fifth

Additionally, the III and VI chords introduced through “quality change” often employ the sharp-fifth.

The technique “quality change” itself has an effect of bringing higher musical tension, and the sharp-fifth adds an extra touch to them.

Notably, in these two cases, raising the 5^th by a half-step does not generate any accidentals. It simply changes from ti to do or from mi to fa. This makes them very much easy to listen to and therefore user-friendly¹.

IV_Δ7IIIVI_m7VI

This is the state with just a simple quality change. Now that we’e learned new chords, it seems like ordinary chords, doesn’t it? Let’s try raising the 5^th of III and VI by a half step.

IV_Δ7III^(♯5)VI_m7VI^(♯5)

As you can hear, the sound becomes more complex and mature, enhancing its sophistication! In this jazz-style piece, this version suits better.

III7⁽⁺⁵⁾ and VI7⁽⁺⁵⁾

In these cases, using them as seventh chords is, of course, possible, resulting in intensified, more addictive chords.

Converting them into seventh chords allows you to attain a more intricate and rich sound.

IV_Δ7III₇⁽⁺⁵⁾VI_m7VI₇⁽⁺⁵⁾

While the difference compared to the previous sound is subtle, this version has more depth and suits the style of this piece better. In mature, sophisticated music like jazz, these seventh chords are usually preferred.

Conversely, in genres like rock or reggae, a simple triad may also be preferred. The choice is similar to the other chords explored so far: whether you prefer a simpler sound or a more intricate one.

Diatonic to the Key

One important point learned this time: Due to the uneven arrangement of whole/half steps in the scale, you encounter the situation where the altered notes needs no accidentals.

As you’ve seen, altering the 5^th of III chord means just changing ti to do. There are no new sharps added. When a note belongs to the original scale of a key, in other words, when it does not require accidentals, the note is described as being Diatonic to the Key. Or referring to it more concisely as a “diatonic note” should generally convey the meaning.

This idea “diatonic to the key” will serve as an important criterion for complicating chords in the future, so keep in mind that such terminology has been specifically provided.

Summary

• By raising the 5^th by a half step, you get a sharp-fifth chord.
• Particularly, the sharp-fifth in major chords is crucial, offering a unique sound.
• Sharp-fifth on I, IV, V is common. Utilizing the upward tendency of 5^th is the key to make use of them.

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