Altered Chords

Are you looking for a way to spice up your chord progressions?

Altered chords are a great way to add some flavor to your music. By altering the major, minor, and dominant chords in various ways, you can create new harmonic possibilities that will make your music sound more interesting.

With our step-by-step guide, you’ll be able to learn how to use an altered chord in your own music in no time. You’ll be able to create richer harmonies, add tension and release, and give your music a more modern sound.

Read our complete detailed article today and start learning about altered chords!

Definition of Altered Chords

To start with, you can think of an altered chord, an alt chord for short, as an extended chord, with one or more notes changed or altered to a chromatic note.

Altered chords are complex chords with many possible variations and definitions that may confuse any new player. But as you will understand, they open out many harmonic options to reward you for your efforts in learning them. The only constraint at this stage is that you must be fully comfortable with the concepts of the seventh and the extended chords.

Back to the definition, the notes of the extended chords, like the 9th, 11th, or 13th chords, are either raised or lowered by one semitone to form an altered chord. We say that the original extended chords have been chromatically altered. In music theory, a chromatic alteration signifies that the new note is not part of the scale from which the chord is built.

The possible chromatic changes to extended chords are:

  • b9 and #9 to the 9th chords,
  • b11 and # 11 to the 11th chords,
  • b13 and #13 to the 13th chords.

You may know that any extended chord can only be Major, minor, or Dominant, and the extensions do not alter the core (up to the 7th note) of the basic 7th chords, they are formed from. The Alt chords retain these qualities and have the same three versions.

Alt Chords

As you are seen, there are three chord qualities and six possible alterations in each, resulting in eighteen possible Alt chords. However, the altered note in some of these 18 chords may already be present in the core seventh chord, an octave below. Let us see which of these changes are possible by going through each version in detail.

Major Chord Alterations

The extended major chords have Major seventh chords with the notes: R, M3, P5, and M7 as the core.

b9 and #9 Variations

The major 9th chords have a major 9th note. If we lower this note by a half step to b9, the new chord can be denoted as Major7b9. In traditional notation, the changes are shown in a bracket and superscripted like Major7(b9). In the major key of C, the notes of CMajor7(b9) are C, E, G, B, and Db.

The b9 note has a minor 9th (minor 2nd) interval from the root, only a semitone above, and causes dissonance. Since the unaltered chord does not have a minor 2nd, b9 results in a valid alteration, being a unique note in the chord.

Let us now try #9, where the 9th note is chromatically raised. A sharp nine is actually a minor 10th (or a minor 3rd). This note is again just one semitone before the major 3rd and may produce a clash with it.

The chord is denoted as Maj7#9 or Maj7(#9), and the notes of CMaj7(#9) are C, E, G, B, and D#. If you choose to leave the Major 3rd note due to a clash, you will get a minor chord with a major 7th note, which is opposite to the intervals of a Dominant 7 chord and the same as a half-diminished 7th chord.

b11 and #11 Variations

A Major 11th has the following notes: R, M3, P5, M7, M9, and P11. As you know, P11 is the same note as P4, an octave above.

The alteration to b11 is equivalent to a Major 10th or a Major 3rd. Since the unaltered chord has a major 3rd, this alteration is not meaningful.

Raising the P11 to #11 results in an augmented 4th, with a semitone interval, with P5. The chord is named Maj9#11 to indicate it as a Major 9th chord with a sharpened 11th. Major11#11 designation does not convey the meaning and can lead to confusion. It is customary to name the altered versions with a label a third below, followed by the altered note. The notes of CMaj9(#11) in the key of the C major scale are C, E, G, B, D, F#

b13 and #13 Variations

The major 13th chords have the notes R, M3, P5, M7, M9, P11, and M13. The note b13 is the same as a minor 13th or a minor 6th note, which is not present in the unaltered chord. It is denoted by Maj11b13. In C, the notes shall be C, E, G, B, D, F, and Ab.

Raising the 13th note to #13 is the same as a minor 14th or a minor 7th note, which is also a unique note in the chord. The chord is denoted as Maj11(#13) with the notes C, E, G, B, D, F, and A# in the key of C.

The table below gives the summary of all the chromatic changes in the Major extended chords.

Altered Major Chords

Minor Chord Alterations

Here, you need to repeat the exercise that you have carried out for the major chords.

b9 and #9 Variations

A minor 7th chord is made up of R, m3, P5, and m7 notes. Extending it to a 9th (M9) and lowering the 9th by one semitone gives us an altered ninth minor chord, denoted by m7b9. The minor 9th interval is the same as a minor 2nd and is unique in the chord. The notes of Cm7b9 are C, Eb, G, Bb, and Db.

Raising the 9th to #9 gives a minor 10th (minor 3rd) note, which already exists in the unaltered note. Hence you need to discard this alteration.

b11 and #11 Variations

The notes of the minor 11th chords are R, m3, P5, m7, M9, and P11. Lowering the P11 to b11 gives a Major 10th (Major 3rd) note, which is unique. This chord also has both Major and minor 3rd notes and is denoted as m9b11. The notes of Cm9b11 are C, Eb, G, Bb, D, and E.

The next chord is formed by raising the 11th note to an Augmented 11th (Aug 4th), which is unique. It is termed as m9#11, and the notes of Cm9#11 are C, Eb, G, Bb, D, and F#.

b13 and #13 Variations

The notes of minor 13th chords are R, m3, P5, m7, M9, P11, and M13. The b13 variation results in the 13th note to a minor 13th (minor 6th), leading to an m11b13 chord. The example includes Cm11b13 with the notes C, Eb, G, Bb, D, F, and Ab.

The #13 alteration leads to a minor 13th (minor 7th) note that is already part of the unaltered chord. Hence you don’t need this alteration.

The table for all the variations in the minor extended chords is presented below for easy reference.

Altered Minor Chords

Dominant Chord Alterations

Dominant chords are more suited for these kinds of chromatic changes, as they are designed for increased tension in the chord progression. An Altered dominant chord increases the tension, even more, resulting in an urgent need to resolve to a stable note. Due to this reason, altered dominant chords are seen more often than the other two.

b9 and #9 Variations

A dominant 9th chord is made up of R, M3, P5, m7, and M9 notes. Lowering the 9th to b9 results in a minor 9th (minor 2nd) note, which is unique. The resulting chord is called 7b9, and the notes of C7b9 are C, E, G, Bb, and Db.

Raising the 9th to #9 results in one of the most popular chords in altered varieties, known as Hendrix’s chord. It is used in funk, rock, blues, and jazz music. Particularly E7#9 is most preferred due to the open E strings.

#9 note is equivalent to a minor 3rd. Hence, this chord carries a minor 3rd, a Major 3rd, and a minor 7th, a combination that sounds really funky. The chord is designated as 7#9, and the notes of C7#9 are C, E, G, Bb, and Eb.

b11 and #11 Variations

The notes of the Dominant 11th chords are R, M3, P5, m7, M9, and P11. Lowering the P11 to b11 leads to a Major 3rd, which is already a part of the dominant seventh chord. Hence this variation is not meaningful.

#11 raises the 11th note to an Augmented 11th (Aug 4th) note. The chord has the name 9#11. C9#11 carries the notes C, E, G, Bb, D, and F#.

b13 and #13 Variations

The notes of the 13th dominant chords are R, M3, P5, m7, M9, P11, and M13. Lowering the 13th to b13 gives a minor 13th (minor 6th note), leading to a 11b13 chord. The notes in C are C, E, G, Bb, D, F, and Ab.

#13 is equal to the minor 14th (minor 7th) note, which already exists in the unaltered chord.

The summary of changes in the 13th chords is given in the table below.

Altered Dominant Chords

To summarize, out of 18 options, only 13 resulted in a valid altered chord, as summarized below.

  1. In Major chords, there is no b11 alteration.
  2. In minor chords, #9 and #13 did not yield an altered option.
  3. b11 and #13 did not provide any altered dominants.

Other Alteration Possibilities

It is also possible for you to directly apply the chromatic alteration directly to the 7th chords without extending the chords. This means that you can simply add a b13 note to the minor seventh chord, thereby creating an m7b13 chord with the notes R, m3, P5, m7, and m13, without the 9th or the 11th note.

Another example of an altered seventh chord is the addition of #11 to a dominant 7th chord, resulting in 7#11 chords with the notes R, M3, P5, m7, and Aug11.

You can go in for more than one alteration in a chord if it makes sense and sounds good. For example, a chord with two alterations is represented by Maj7(b9 #11), with a space in between the two changes shown inside the parenthesis.

Use of b5 and #5

You may sometimes come across an alteration noted as b5 or #5, which denotes a lowered fifth and a raised fifth. Don’t get confused, as this is just a different nomenclature for the changes we had gone through earlier.

The b5 is the same note as #11, an octave lower. #11 is used on the major chord, while b5 is used to designate the minor and dominant chords. The purpose of using b5 instead of #11 is just to avoid the use of both sharp and flats to denote a single chord.

For example, the Gm7#11 chord has the notes G, Bb, D, F, and C#. So by using b5 instead of #11, we denote it as G, Bb, D, F, and Db. It is a personal preference of the composer or arranger. Some theorists don’t prefer the use of the same alphabet in the chord but are happy with flats and sharps together.

The same logic is applicable for #5 and b13 designations.

Some composers use a flat symbol in the chord if the chord is traveling downwards and sharp when it is traveling upward.

By the way, b9, #9, #11, and b13 are the most commonly used altered notes on dominant chords in Jazz music.

Borrowed Chords & Secondary Dominants

A secondary dominant, also sometimes referred to as the borrowed dominant, is either a major triad or a dominant 7th chord that is specifically built to resolve instead of the tonic note to some other scale degree. Most often, this note is the dominant note of the dominant scale degree, denoted as V/V. In the key of C major, V/V is the D major triad (the V of G Major).

V/ii, or V of ii, demotes the dominant of the ii chord Dm (A) in the key of C Major, and so on. The purpose of any secondary dominant chord is to place emphasis on any chord in the chord progression, as any dominant chord tends to resolve to its tonic. The ii chords, in this case, are said to be temporarily tonicized. The tonic itself and the vii° diminished chord are not tonicized. Hence secondary dominants are there for the balance of five scale degrees.

It is quite common to use the dominant 7th chords as the secondary dominants.

Borrowed Chords vs Altered Chords

We had gone through the definition of an altered chord at the beginning of the article. However, there is a minor difference in how classical and jazz music consider this definition. As per the classical viewpoint, the term altered chord is used if the altered note does not belong to the original scale. Thereby, the chord no longer fits the key.

As per the classical view, if the altered note belongs to the original scale, the resultant chord is not an altered chord. While modern Jazz view considers it an altered chord.

The out-of-key chord is also known as a borrowed chord or a non-diatonic chord, as it carries a non-diatonic note.

You might remember the meaning of the term “parallel mode.” The parallel modes share the same root note but belong to different parent scales. An altered chord usually belongs to the parallel mode, and the borrowing process is known as a modal mixture or modal interchange.

Consider the chord progression in the key of C major,

Cmaj7 – Am7 – Fmaj7 – G7.

If you change the F major chord to F minor, the progression changes to

Cmaj7 – Am7 – Fm7 – G7.

While the whole progression still belongs to the key of C major, one of the chords, Fm7, belongs to the key of C minor. Since C major and C minor are parallel modes, we have borrowed one chord from the parallel mode. The new chord Fm7 has altered notes.

Instead, if we alter the Fmaj7 chord to Fmaj7#11 with notes F, A, C, E, B. All these notes are in the key of C major. Hence as per the classical view, this is not an altered chord, but modern jazz considers it as so.

Altered Harmony – Where Do Altered Chords Come From?

Do you remember the altered scale from the discussion on the melodic minor scales? Let us remind you that it is the 7th mode of the melodic minor scale and is particularly used by jazz guitar players in more sophisticated chords and lead lines over these chords. It has the other name, “Super Locrian.” The original melodic minor scale is the 2nd mode of the altered scale or on its second degree.

We had stated earlier that altered notes are used more over the dominant chords in a chord progression, with such chords being known as the dominant functioning chords. These altered dominant chords allow you to play lead lines over them and use the altered scales over them before the resolution and are often used by jazz players in their solos.

The notes of an altered scale are 1, b2, b3, b4, b5, b6, b7, 1(8). In the key of C, the notes will be C, Db, Eb, Fb, Gb, Ab, Bb, and C.

Building Altered Scale from Dominant Chord

It is possible to build this scale from the dominant chord C7. Let us see how?

The C7 chord has the notes C, E, and Bb. Let us add the four altered notes possible for the dominant chords, as seen above. The b9, #9, b5 (or #11) and #5 (or b13). We have not shown the fifth note as we are going to an altered version, b5 and #5 of this note.

Now we have C in the root position, Db (b9), D# (#9), E (3), Gb (b5), G# (#5), and Bb (b7). Renaming the notes with their enharmonic equivalents, we get

C (1), Db (b9), Eb (#9), Fb (3), Gb (b5), Ab (#5), and Bb (b7). These are exactly the notes of the C altered scale.

DescriptionNote 1Note 2Note 3Note 4Note 5Note 6Note 7
Dominant Chord Notes13b7
C7 NotesCEBb
Dominant Chord With Altered NotesRb9#93b5#5b7
Altered C7 NotesCDbD#EGbG#Bb
Final C Altered Scale with enharmonic equivalentsCDbEbFbGbAbBb

As stated earlier, the dominant chords carry out the function of building up tension before it is resolved. The Mixolydian mode, or the dominant scale, has the notes C, D, E, F, G, A, and Bb. So altered scale has 1, 3, and 7th notes the same as the dominant scale, and all other notes are altered. Hence altered scale works its best over the dominant chords.

How are Altered Chords Used?

The various uses you can put the altered chords for are:

As a modal mixture of chords

You have seen this option in detail with an example in the section on Borrowed chords vs. Altered chords, where the Major IV chord is changed to a minor one. Other options include changing an ii minor chord to a diminished one. The out-of-key (minor or diminished) chord has a surprise element in a musical piece that momentarily pulls it out of the strong tonality and adds color.

Using a secondary dominant chord

You had an introduction to the secondary dominants in earlier sections. Try changing the minor chord, like ii (Dm in the key of C), to a major or dominant chord (D or D7). If the next chord has a root G, whose 5th is the root of this chord, then D or D7 will resolve to the next chord.

Using a Flat-III, Flat-VI, or Flat-VII.

They provide you with other options for modal mixtures, as the notes are not in the chosen key of the scale. The purpose is, again, to create movement by taking the music in a slightly different direction.

How Are Altered Chords Resolved?

Any dominant 9th chord has a tendency to resolve to a major chord (triad, 7th, or 9th major chord) that is 5th below its root. Hence D9 will resolve to G major triad or GMaj7 or GMaj9 chord.

The altered chords resolve to a minor chord (a triad, 7th or 9th chords) having a root 5th below the root of the altered chord. Or, they resolve to a major chord (triad, 7th, or 9th major chord) that is one semitone below its root.


In this blog post, we explored altered chords and how they can be used in Classical and Jazz Music. We looked at the different types of alterations and their effect on the overall sound of a chord. By understanding altered chords, you’ll be able to add more creativity and interest to your playing. If you have any questions or want clarification on anything, let me know in the comments section below.

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