Enharmonic Equivalents: Notes, Scales, Keys and Intervals

The term enharmonic if you haven’t heard it before, can be quite confusing. You’ll often get asked about it in a grade five music theory exam so it’s definitely worth learning for some easy marks.

In this post we’re going to be looking at some examples of what enharmonic equivalents are and how they’re used in reading and writing music.

What does enharmonic mean?

Although it sounds quite complicated, enharmonic essentially is an ‘alternate name for the same thing’.

For example, you could have a note like C# but you could also call this note Db. They are the same note but have different names and so are enharmonic equivalents.

Types of enharmonic equivalents

There are actually lots of different types of enharmonic equivalents. You can have enharmonic equivalent:

  • Notes
  • Scales
  • Chords
  • Keys
  • Intervals

We’ll go into some examples now to explain how they work.

Enharmonic equivalent notes

Notes can have more than one name. For example, this note here could be either C sharp (C#) or D flat (Db) depending on how you look at it.

You could also call it B double sharp, all are correct but it depends on what context you’re playing the note.

When you have notes like this that are the same but with different names they are called enharmonic equivalents.

Whether you’d call it D flat, C sharp or B double sharp depends on what key you’re in. For example, if we were in the key of Ab then we’d call this note Db as Ab has four flats in its key signature: Bb, Eb, Ab and Db.

But if we were in the key of E major then it would be C# as E major has four sharps in its key signature: F#, C#, G# and D#.

If we were in the key of C# major then it would be B double sharp as C# major has seven sharps it its key signature: F#, C#, G#, D#, A#, E#, and B#

Enharmonic equivalent scales

As well as enharmonic equivalent notes you can have enharmonic equivalent scales and they work in exactly the same way.

For example, if we take the scale Gb major which has the notes: Gb – Ab – Bb – Cb – Db – Eb – F

Gb major scale

The enharmonic equivalent scale would be F# major which has the same notes but spelt differently: F# – G# – A# – B – C# – D# – E#

F# major scale

Enharmonic equivalent key and chords

An enharmonic equivalent key are those that have the same pitches but with different names. It works in the same way as scales and notes for example C# major and Db major are enharmonic equivalent keys as the underlying pitches are the same but C# major uses sharps and Db major uses flats.

C# major
Db major

You might wonder why you might use one key over the other? The main reason is that some keys have fewer flats or sharps than others and can be a lot easier to read.

For instance, in the case of C# and Db major, most people would prefer to play in Db major as it only has five flats as oppressed to C# major which has seven sharps.

Or if you had the choice of playing in Cb major (which has seven flats) or B major (which has five sharps) which would you choose?

Cb major
B major

Enharmonic equivalent intervals

Enharmonic equivalent intervals are slightly different from notes, scales and keys but follow the same principle. An enharmonic interval is two notes that are the same distance apart but spelt differently. For example let’s take the two notes C and E which is a major 3rd.

But, Fb is an enharmonic equivalent of E natural so we could also write this interval as C to Fb which although is the same amount of semitones apart is now described as a diminished 4th instead of a major 3rd.

Major 3rd
Diminished 4th

Wrapping up enharmonic equivalents

I hope that helps make a bit more sense of enharmonic equivalents. It can seem a bit confusing and overwhelming at first, but once you get the hang of seeing notes, scales, keys and intervals as being more than one thing it should start to sink in. If you have any questions that I haven’t covered in this post just comment below.

Dan Farrant

Dan Farrant

Dan Farrant, the founder of Hello Music Theory, has been teaching music for over 10 years helping thousands of students unlock the joy of music. He graduated from The Royal Academy of Music in 2012 and then launched Hello Music Theory in 2014. Since then he's been working to make music theory easy for over 1 million students in over 80 countries around the world.

4 thoughts on “Enharmonic Equivalents: Notes, Scales, Keys and Intervals”

  1. Hi Moses,

    If you’re playing them they’re exactly the same, the only difference is if you were to write them down. Written down they look very different!

  2. Hi, Dan. Thanks so much for the clarity of this page on enharmonic equivalents. Two questions: Let’s say you have a two-note chord with a C on the bottom and Ab on top. We’d call that a Minor 6th. If we spell the C as a Dbb is the interval an augmented 5th? This is very confusing as I’ve always associated an interval’s name with its sound. In this case, it certainly sounds like a Minor 6th, but we’re calling it a diminished 5th.
    And, in working with enharmonic equivalents, if one note in a chord is, say, flatted, could another be sharped, or do all the notes in the chord have to conform and be either flatted or sharped? In the example above, let’s call the lower note a B#. If the upper note is Ab, what’s the interval? I can’t wrap my head around this, somehow. It’s obviously some kind of 7th–a diminished 7th? Help!

    Thanks, and I so look forward to hearing from you. Be well, Steve

  3. Hi Steve, You’re absolutely right in your first question. The interval is named by how it’s written and not necessary how it sounds. In practice we tend to opt for the easiest way to name the interval so will usually opt for minor 6th over augmented 5th. An example of this in practice is the harmonic minor scale. The interval between the 6th and 7th notes is a three semitones, which is usually named a minor 3rd (In C harmonic minor would be Ab and B. But if it were a minor 3rd then we’d write it as Ab and Cb which in C harmonic minor would be wrong as then you’d have Cb and C natural in the scale. So in this case it would have to be an augmented 2nd rather than a minor 3rd. Does that make sense?

    And yes you’re also correct in the 2nd question. You can have both flat and sharp notes in an interval or chord. The example you’ve brought up is rare but would be a doubly diminished 7th. You use the word doubly to signify larger or small interval than diminished or augmented. A useful calculator is this one from MusicTheory.net. Hope that helps!

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