Ionian #5 Mode on Guitar: Notes, Chords & Examples

  • May 21, 2026

The Ionian ♯5 mode is a bright, major-sounding mode with an unexpected twist: a raised 5th.

At first, it feels close to the regular major scale. You still get the happy major 3rd, the open major 6th, and the smooth major 7th. But the ♯5 adds a floating, surreal, almost “bent reality” quality.

For guitarists, Ionian ♯5 sounds:

  • Bright but unstable
  • Dreamy and cinematic
  • Major, but not ordinary
  • Slightly mysterious or futuristic
  • Great for progressive rock, fusion, film-score moods, and advanced songwriting

It is also known as Ionian augmented because the tonic chord is an augmented major chord.

Ionian ♯5 is the 3rd mode of harmonic minor

How does it sound?

Before anything else, let’s hear how it sounds. This can best be done by playing a chord from the mode, and playing the notes of the mode arpeggiated on top of it. This is the best and quickest way to determine the feel of a mode.

This can be quickly done using SLModes, a software dedicated to the music modes, and the following sound was generated by it:

Formula

The interval formula for Ionian ♯5 is:

1 2 3 4 ♯5 6 7

Compared to the regular Ionian mode, or major scale:

1 2 3 4 5 6 7

Ionian ♯5 changes only one note:

5 becomes ♯5

That one change makes a huge difference.

In C major, the 5th is G.

In C Ionian ♯5, the 5th becomes G#.

Notes in C

The notes of C Ionian ♯5 are:

C D E F G# A B

Interval breakdown:

  • C = 1
  • D = 2
  • E = 3
  • F = 4
  • G# = ♯5
  • A = 6
  • B = 7

This gives you a major scale sound with an augmented color in the middle.

The Chord That Defines the Mode

The defining chord of Ionian ♯5 is:

Cmaj7♯5

Notes:

C E G# B

Formula:

1 3 ♯5 7

This chord captures the mode better than any other chord because it contains the two most important ingredients:

  • The major 3rd: E
  • The raised 5th: G#
  • The major 7th: B

Together, these notes create a sound that is major, elegant, and unstable.

A simple C augmented triad also works:

C E G#

But Cmaj7♯5 gives you the full modal identity. The major 7th makes the chord feel more sophisticated and less like a simple augmented passing chord.

On guitar, try this voicing:

Cmaj7♯5

e|--0--
B|--0--
G|--1--
D|--2--
A|--3--
E|-----

Notes:

  • A string 3rd fret = C
  • D string 2nd fret = E
  • G string 1st fret = G#
  • B string open = B
  • High E open = E

It has a strange, open, beautiful sound.

Chord Progression (Example)

Because Ionian ♯5 is not as common as major, minor, Dorian, or Mixolydian, the safest way to keep the mode clear is to emphasize the Imaj7♯5 chord.

In C Ionian ♯5, the main chords are:

  • Imaj7♯5 = Cmaj7♯5
  • ii7 = Dm7
  • III7 = E7
  • IVmaj7#11 = Fmaj7#11
  • #v°7 = G#dim7
  • vi m(maj7) = Am(maj7)
  • viiø7 = Bm7b5

Roman numerals:

Imaj7♯5 – IVmaj7#11 – Imaj7♯5

Chords in C:

Cmaj7♯5 – Fmaj7#11 – Cmaj7♯5

This progression sounds wide, floating, and cinematic.

The Cmaj7♯5 gives you the core Ionian ♯5 sound, while Fmaj7#11 adds a progressive, dreamy color.

Try playing it slowly with clean guitar, chorus, delay, or shimmer reverb.

Guitar Fretboard Shape

Here’s the mode mapped across the full fretboard, generated with my software SLModes.

The diagram shows every occurrence of the mode across the neck:

🟢 Green dots = the root note, your anchor points
🟠 Orange dots = the rest of the scale tones

Why Guitarists Love This Mode

Ionian ♯5 is not an everyday mode, and that is exactly why it is useful.

Emotional Flavor

The mode sounds major, but not simple.

It can feel:

  • Bright
  • Strange
  • Floating
  • Elegant
  • Futuristic
  • Slightly tense

The raised 5th makes the whole scale feel like it is lifting upward.

This is great when regular major sounds too predictable, but you do not want to go fully minor or dark.

Riff Potential

Ionian ♯5 can create unusual riffs because of the augmented triad inside the mode.

In C Ionian ♯5, the tonic augmented triad is:

C E G#

That shape divides the octave into major 3rds, which creates a symmetrical, progressive sound.

Try building riffs around:

C - E - G# - E

Or:

C - D - E - G# - A - G#

The jump from E to G# immediately gives the riff a more exotic flavor.

For progressive metal, try using a low C pedal tone while moving upper notes from the scale:

C pedal + E, F, G#, B

That combination gives you tension without sounding like standard harmonic minor shredding.

Soloing Applications

Ionian ♯5 works well over:

  • Cmaj7♯5
  • C augmented
  • Cmaj9♯5
  • Cmaj13♯5
  • Modal C pedal vamps
  • Fusion progressions with augmented major chords

When soloing, do not just run the scale up and down.

Instead, emphasize the defining tones:

  • E = major color
  • G# = augmented color
  • B = elegant major 7th

The natural 4th, F, is spicy against the E in Cmaj7♯5.

Use it carefully.

F often sounds best when it resolves to E or moves up to G#.

Genres Where It Works Well

Ionian ♯5 fits especially well in:

  • Progressive rock
  • Progressive metal
  • Jazz fusion
  • Instrumental guitar music
  • Cinematic songwriting
  • Ambient guitar
  • Game and soundtrack-inspired music
  • Modern metal clean sections

It is not usually a “blues-rock jam” mode.

It shines when the harmony is more colorful and the arrangement gives the mode space.

Tips for Practicing

1. Practice With a C Drone

Start with a simple C drone.

You can use:

  • A looper pedal
  • A synth pad
  • A bass note
  • A DAW drone
  • An open C tuning idea
  • A sustained C power chord without the 5th

Play the scale slowly over the drone:

C D E F G# A B C

Listen closely to how each note feels.

Pay special attention to:

  • E against C
  • G# against C
  • B against C
  • F resolving to E

The ♯5 is the main color, so do not hide it.

2. Use Simple Chord Vamps

Try looping one of these:

Cmaj7♯5

Or:

Cmaj7♯5 - Fmaj7#11

Or:

Cmaj7♯5 - Dm7 - Cmaj7♯5

Keep the harmony simple at first.

The more chords you add, the easier it is for the music to sound like A harmonic minor instead of C Ionian ♯5.

3. Improvise With Arpeggios

Start with the defining arpeggio:

C E G# B

That is Cmaj7♯5.

Then add passing notes from the mode:

D, F, A

For example:

C - E - G# - B - A - G# - F - E

This line clearly shows the mode:

  • Major chord tones
  • Raised 5th
  • Natural 4 resolving to 3

4. Target the Important Intervals

When practicing, aim for specific intervals instead of random scale notes.

Target these:

  • 3: E
  • ♯5: G#
  • 7: B
  • 4 to 3 resolution: F to E
  • 6 to ♯5 motion: A to G#

Great Ionian ♯5 phrases often highlight the tension between familiar major sounds and the unstable ♯5.

If you like modes, SLModes is for you

SLModes is the software for exploring everything related to music modes.

It helps you experiment with:

  • Modal chords
  • Guitar fretboard shapes
  • Chord progressions
  • Modal modulation
  • Negative harmony ideas

If you play guitar and want to access 60+ music modes, SLModes is waiting for you

Learn more about SLModes

Join the Newsletter

Interested in music theory like this? Leave your email below and I’ll keep you updated.