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. For example, Ionian #5 comes from harmonic minor:

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 Progressions

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

Progression 1

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.

Progression 2

Roman numerals:

Imaj7#5 – ii7 – viiø7 – Imaj7#5

Chords in C:

Cmaj7#5 – Dm7 – Bm7b5 – Cmaj7#5

This progression has a smoother, more jazz-fusion flavor.

The Dm7 softens the sound, while Bm7b5 creates tension before resolving back to Cmaj7#5.

It works well for:

  • Fusion backing tracks
  • Modal solo sections
  • Clean progressive rock passages
  • Ambient guitar loops

Progression 3

Roman numerals:

Imaj7#5 – #v°7 – vi m(maj7) – III7 – Imaj7#5

Chords in C:

Cmaj7#5 – G#dim7 – Am(maj7) – E7 – Cmaj7#5

This one leans more into the harmonic minor parent scale.

Remember: C Ionian #5 comes from A harmonic minor. Because of that, chords like Am(maj7) and E7 can pull your ear toward A minor.

That is not a bad thing. It creates a dark, dramatic contrast.

To keep C as the center, return strongly to Cmaj7#5 and use C pedal tones in the bass or rhythm guitar.

Famous Songs and Guitarists Using Ionian #5

Ionian #5 is a rare mode in popular guitar music.

There are not many famous rock or metal songs that are clearly and consistently “in Ionian #5” as a tonal center. It is much more common to hear the maj7#5 chord color than to hear an entire song written strictly in this mode.

That said, the sound is commonly associated with:

  • Jazz-fusion harmony
  • Progressive rock and metal
  • Film and game music
  • Harmonic minor-based composition
  • Augmented major chord movement

Guitarists who explore related augmented-major and advanced modal colors include:

  • Allan Holdsworth
  • Frank Gambale
  • Pat Metheny
  • Steve Vai
  • Jason Becker
  • John McLaughlin

Important note: many fusion players use Lydian augmented over maj7#5 chords more often than Ionian #5.

Lydian augmented is:

1 2 3 #4 #5 6 7

Ionian #5 is:

1 2 3 4 #5 6 7

The difference is the 4th:

  • Ionian #5 has natural 4
  • Lydian augmented has #4

So if a guitarist plays over Cmaj7#5 and uses F natural, that points more toward C Ionian #5.

If they use F#, that points more toward C Lydian augmented.

Guitar Fretboard Shape

Here is a practical C Ionian #5 shape around the 8th position.

Notes:

C D E F G# A B

C Ionian #5

e|---------------------------10-12-13-|
B|--------------------10-12-13--------|
G|--------------9-10-13---------------|
D|---------9-10-12--------------------|
A|--8-11-12---------------------------|
E|--8-10-12---------------------------|

Root notes are C:

e|---------------------------10-12-13-|
B|--------------------10-12-13--------|
G|--------------9-10-13---------------|
D|---------9-10-12--------------------|
A|--8-------------------------------|
E|--8-------------------------------|

Useful target notes:

  • C = root
  • E = major 3rd
  • G# = #5
  • B = major 7th

For the strongest Ionian #5 sound, target E, G#, and B over a C bass note.

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.

Try This Mode in SLModes

Want to explore Ionian #5 more deeply?

Try it in SLModes.

SLModes helps you hear and visualize modes through:

  • Interactive chord options
  • Guitar fretboard layouts
  • Modal modulation tools
  • Scale and chord relationships
  • Negative harmony exploration

For Ionian #5, you can quickly compare the sound of Cmaj7#5, related harmonic minor chords, and nearby modal colors like Lydian augmented.

Use SLModes to build vamps, test chord progressions, explore fretboard shapes, and discover how this unusual major mode can fit into your own riffs, solos, and songs.