Key Signatures to Know for Intro to Music Theory

Key signatures are essential in music, defining the mood and structure of a piece. They help distinguish between major and minor sounds, guide transitions, and reveal relationships between keys, making them crucial for understanding music theory and musicianship.

1. Major and minor key signatures

   • Major key signatures have a bright, happy sound, while minor key signatures evoke a darker, sadder tone.
   • Each major key has a corresponding minor key that shares the same key signature.
   • The tonic note defines the key, with major keys starting on the first scale degree and minor keys starting on the sixth scale degree.

2. Circle of fifths

   • The Circle of Fifths visually represents the relationship between different key signatures.
   • Moving clockwise adds sharps, while moving counterclockwise adds flats.
   • Each step around the circle represents a perfect fifth interval, helping to understand key relationships and transitions.

3. Key signature order of sharps (FCGDAEB)

   • The order of sharps in key signatures is fixed: F, C, G, D, A, E, B.
   • Each new sharp is added in this specific order as you move to higher key signatures.
   • The last sharp added indicates the leading tone of the key, one half step below the tonic.

4. Key signature order of flats (BEADGCF)

   • The order of flats in key signatures is also fixed: B, E, A, D, G, C, F.
   • Each new flat is added in this specific order as you move to lower key signatures.
   • The second-to-last flat indicates the tonic of the key signature.

5. Relative major and minor keys

   • Relative major and minor keys share the same key signature but have different tonics.
   • The relative minor is located a minor third below the major key (or a major sixth above).
   • Understanding relative keys helps in modulation and composition.

6. Parallel major and minor keys

   • Parallel keys share the same tonic note but have different key signatures.
   • For example, C major and C minor have different sets of sharps or flats.
   • This relationship is important for exploring contrasting moods within a piece.

7. Enharmonic keys

   • Enharmonic keys are keys that sound the same but are written differently (e.g., C# major and Db major).
   • They have different key signatures and are used in different musical contexts.
   • Understanding enharmonic equivalents is crucial for reading and interpreting music accurately.

8. Key signature rules for major keys

   • Major keys have a specific number of sharps or flats based on their position in the Circle of Fifths.
   • The tonic note is the first note of the major scale, and the scale follows a whole and half-step pattern.
   • The key signature is determined by the last sharp or the second-to-last flat, depending on the key.

9. Key signature rules for minor keys

   • Minor keys also follow a specific number of sharps or flats, similar to major keys.
   • The tonic note is the sixth note of the major scale, and the minor scale has a different whole and half-step pattern.
   • The key signature is determined by the relative major key's signature or by the specific minor key rules.

10. How to identify a key signature

• Look for the sharps or flats at the beginning of a piece of music to determine the key signature.
• Use the order of sharps (FCGDAEB) or flats (BEADGCF) to identify the specific key.
• Remember the relationship between major and minor keys to find the relative key signature if needed.