Chapter 2: Understanding Enharmonic Scales, Theoretical Keys & the Circle of Fifths

After learning about major scales with sharps and flats, it is time to explore enharmonic scales. Understanding these scales is essential to fully grasp the Circle of Fifths and how all key signatures relate.

Enharmonic Scales

Now that we have analysed major scales and their key signatures with sharps and flats, let’s talk about enharmonic scales.

Understanding Enharmonic Scales

Enharmonic scales have a different key note and key signature, but they sound exactly the same.
On the piano, the same keys produce the same pitches.
Theoretical naming makes them appear different, but they are identical in sound.

Studying enharmonic scales helps you:

• Understand the full logic of the Circle of Fifths.
• Recognize every possible key signature.
• Connect the “sharp side” and “flat side” of the Circle.

Enharmonic Major Scales

Common Enharmonic Pairs

• F♯ Major ↔ G♭ Major
  • F♯ is the key note of F♯ Major.
  • G♭ is the key note of G♭ Major.
  • F♯ Major has six sharps; G♭ Major has six flats.
  • Different key names and key signatures, but the two scales sound exactly the same.
  • Every note in both scales corresponds to the same piano key.
    
• C♯ Major ↔ D♭ Major
  
• B Major ↔ C♭ Major

In classical music, only these three enharmonic major pairs are commonly used: F♯/G♭, C♯/D♭, B/C♭.

Theoritical Scales

Some enharmonic scales are considered theoretical. They exist only on paper because writing them requires too many sharps, flats, or even double sharps and double flats. Musicians do not use these scales in real notation or performance. Their main purpose is theoretical: they show how the Circle of Fifths continues in both directions. Theoretical scales also help us understand how enharmonic equivalents connect the “sharp side” and the “flat side” of the Circle. Including these scales in study allows you to see the full logic of the Circle of Fifths and understand how all key signatures relate to each other, even the ones we rarely encounter in practice.

G♯ Major ↔ A♭ Major

• G♯ Major is theoretical because it requires an F double sharp.
• Double sharps are not part of standard key signatures.
• In practice, musicians use A♭ Major instead.

D♯ Major ↔ E♭ Major

• D♯ Major requires F double sharp and C double sharp.
• These extra accidentals do not appear in standard notation.
• E♭ Major is used in real music.

A♯ Major ↔ B♭ Major

• A♯ Major requires F, C, G double sharp.
• B♭ Major is used instead.

E♯ Major ↔ F Major

B♯ Major ↔ C Major

Theoretical scales include all sharps or flats of a standard key signature plus any required double sharps or double flats to maintain the correct pattern of whole and half steps.

The sequence of sharp key signatures can include enharmonic equivalents, shown with smaller notes as alternative names. Using enharmonic scales, this sequence can also be reversed to form the sequence of flat key signatures. Both sequences ultimately lead back to C Major.

Enharmonic Sequences and the Circle of Fifths

The Circle of Fifths diagram helps visualize this relationship clearly. Reading the circle clockwise shows the sequence of key signatures with sharps. Reading counterclockwise shows the sequence with flats. Understanding this pattern allows you to predict key signatures quickly and see how all keys connect through enharmonic equivalents.

The Circle of Fifths diagram makes this easier to understand:

• Clockwise → sharp key signatures
• Counterclockwise → flat key signatures

Closing the Chapter

These are the key concepts for understanding major scales with sharps and flats and how the Circle of Fifths works. We also covered enharmonic scales and theoretical scales.

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