Using the Circle of Fifths for Minor Keys

Introduction

• This lecture discusses using the Circle of Fifths to calculate key signatures for minor keys.
• It's recommended to be familiar with the Circle of Fifths for major keys first.

Key Concepts

• Central Reference Points:

  • Major Keys: Use C as the reference point (C major has no sharps/flats).
  • Minor Keys: Use A as the reference point (A minor has no sharps/flats).

• Circle of Fifths:

  • Keys on the sharp side of A have sharps.
  • Keys on the flat side of A have flats.

Minor Keys: Complexity

• Different types of minor keys (melodic and harmonic) use the same key signature but require adjustments.
• Example: C minor has a key signature of 3 flats.

Creating Scales

• Harmonic Minor Scale:

  • Raise the 7th note by a semitone (e.g., C harmonic minor: raise B flat to B natural).

• Melodic Minor Scale:

  • Raise both the 6th and 7th notes by a semitone (e.g., C melodic minor: raise A flat to A natural and B flat to B natural).

Using the Circle of Fifths

• E Minor Example: One notch away from A (1 sharp).
• B Minor Example: Two notches away from A (2 sharps).
• G Minor Example: Two notches away on the flat side (2 flats).

Enharmonic Equivalents

• Necessary for using the Circle of Fifths for all minor keys.
• Enharmonic Equivalent Notes:
  • G flat = F sharp
  • D flat = C sharp
  • A flat = G sharp
  • E flat = D sharp
  • B flat = A sharp

Examples

• B Flat Minor:
  • Travel on the flat side: 5 flats in its key signature.
• G Sharp Minor:
  • Travel on the sharp side: 5 sharps in its key signature.
• A Flat Minor:
  • 7 flats in its key signature.

Order of Sharps and Flats

• Mnemonic: "Father Christmas Gave Dad An Electric Blanket"

  • Top row: Order of Sharps
  • Bottom row: Order of Flats

• Examples:

  • E Minor: 1 sharp (F sharp)
  • B Minor: 2 sharps (F sharp, C sharp)
  • C Minor: 3 flats (B flat, E flat, A flat)

Conclusion

• The Circle of Fifths helps in calculating key signatures, but additional adjustments are needed for different types of minor scales.
• Understanding enharmonic equivalents and the order of sharps/flats is crucial for mastering minor key signatures.