Ionian #2 #5 Mode on Guitar: Notes, Chords & Examples

Ionian ♯2 ♯5 is a bright but strange major-based mode with an augmented, almost cinematic edge. It sounds “major” because it has a natural 3rd and major 7th, but the raised 2nd and raised 5th make it feel unstable, exotic, and futuristic.

For guitarists, this mode sits somewhere between:

A dreamy major scale
An augmented fusion color
A progressive rock/metal synthetic scale
A film-score style “mystery major” sound

It is not a common everyday mode like Dorian or Mixolydian. It is an advanced synthetic mode, so its power comes from using the color notes carefully rather than just running the scale up and down.

In C, the mode is especially striking because it contains two tight chromatic clusters:

D# E F
G# A B C

Those half-step movements are perfect for eerie melodies, angular riffs, and modern fusion lines.

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 ♯2 ♯5 is:

1 ♯2 3 4 ♯5 6 7

In interval names:

P1 A2 M3 P4 A5 M6 M7

Compared to the regular Ionian mode, also known as the major scale, Ionian ♯2 ♯5 raises the 2nd and the 5th:

C Ionian: C D E F G A B C Ionian ♯2 ♯5: C D# E F G# A B

The result is still major, but much more tense and colorful.

Notes in C

The notes of C Ionian ♯2 ♯5 are:

C D# E F G# A B

Because this is an altered major mode, spelling matters.

You may notice that D# sounds like Eb, and G# sounds like Ab. But theoretically, they are written as ♯2 and ♯5 because the mode is built from a major/Ionian framework with raised scale degrees.

So the correct scale-degree spelling is:

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

The Chord That Defines the Mode

The defining chord of C Ionian ♯2 ♯5 is:

Cmaj7♯5(#9)

Notes:

C E G# B D#

This chord captures the sound of the mode beautifully because it includes the most important color tones:

C = root
E = major 3rd
G# = raised 5th / augmented color
B = major 7th
D# = raised 2nd, usually heard as #9 in chord form

A simpler version is:

Cmaj7♯5

Notes:

C E G# B

This already gives you the dreamy augmented-major sound. But adding the D# brings out the full personality of the mode.

On guitar, try this chord shape:

Cmaj7♯5(#9)

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

This is not a basic campfire chord. It is tense, colorful, and very useful for fusion, progressive rock, cinematic metal, and modern songwriting.

Chord Progression (Example)

Because C Ionian ♯2 ♯5 is an advanced synthetic mode, it works best with modal vamps and color-based progressions rather than traditional major-key harmony.

The goal is to keep C feeling like home while using chords that highlight the raised 2nd and raised 5th.

Roman numerals:

Imaj7♯5(#9) – IVmaj7 – Imaj7♯5

Chords in C:

Cmaj7♯5(#9) – Fmaj7 – Cmaj7♯5

This progression moves from the strange augmented tonic to a warmer IV chord.

Mood: Floating, cinematic, mysterious, but still emotionally “major.”

The Fmaj7 gives the ear a more familiar place to rest, while the return to Cmaj7♯5 brings back the unstable Ionian ♯2 ♯5 flavor.

Try soloing over this vamp and emphasizing:

D# resolving to E
G# resolving to A
B resolving to C

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

C Ionian ♯2 ♯5 is bright, but not simple.

It has a major tonic, a major 7th, and a natural 6th, so it can sound beautiful and open. But the ♯2 and ♯5 add tension, mystery, and unease.

It is a great mode when regular major sounds too plain, but you still want something with a strong major identity.

Genres Where It Works Well

C Ionian ♯2 ♯5 can work in:

Progressive rock
Progressive metal
Fusion
Modern jazz guitar
Instrumental rock
Film/game music
Experimental songwriting
Ambient guitar music

It is especially useful when you want a sound that is major, but twisted.

Tips for Practicing

To practice a mode effectively, you only need two things:

An instrument to play the mode (your guitar is ready to go!)
A backing track that provides a harmonic context

The fretboard diagram above already show you where the notes are. The remaining piece is choosing an appropriate backing track to improvise over.

Practice with a drone

The simplest option is a single C drone.

You can create one using:

A looper pedal
A synth drone
A sustained bass note in your DAW
An open C tuning
Or any other source of a continuous C note

Because the accompaniment consists of only a single note, you are responsible for highlighting the intervals that define the mode. The more intentionally you emphasize its characteristic tones, the more clearly the modal sound will emerge.

Create modal vamps with SLModes

While a drone is an excellent way to hear a mode in isolation, a modal vamp often provides a more musical and rewarding practice experience.

A well-designed backing track naturally emphasizes the mode’s characteristic intervals, allowing you to focus on phrasing, melody, and expression instead of constantly trying to establish the modal sound yourself. As a result, improvising in the character of the mode often feels more intuitive.

There are many ways to build modal backing tracks, but SLModes can generate them for you in just a few clicks. For example:

Arpeggiated backing tracks — a repeating pattern that outlines every note of the mode.
Chord vamps — progressions built from chords that best reinforce the mode’s unique character.

This video shows you an example: