Key Signatures & The Circle of Fifths
Key signatures tell you which sharps or flats apply to an entire piece. The Circle of Fifths is your map to all 12 major and minor keys.
Learning Goals
Lesson Content
What Is a Key Signature?
A key signature is the set of sharps or flats printed at the beginning of each staff line. It tells you which notes are consistently altered throughout the piece, so the composer does not have to write an accidental every time.
The Circle of Fifths
The Circle of Fifths arranges all 12 keys in a circle. Moving clockwise, each key is a perfect 5th higher and adds one sharp. Moving counter-clockwise, each key is a perfect 5th lower and adds one flat.
- Sharp keys (clockwise): C, G (1#), D (2#), A (3#), E (4#), B (5#), F# (6#)
- Flat keys (counter-clockwise): C, F (1b), Bb (2b), Eb (3b), Ab (4b), Db (5b), Gb (6b)
Order of Sharps and Flats
- Sharps: F# - C# - G# - D# - A# - E# - B# ("Father Charles Goes Down And Ends Battle")
- Flats: Bb - Eb - Ab - Db - Gb - Cb - Fb (reverse: "Battle Ends And Down Goes Charles' Father")
Finding the Key
For sharp keys: the last sharp is the 7th scale degree — go up one half step to find the key. For flat keys: the second-to-last flat is the key (except F major, which has just one flat).
Practice Activities
Activity 1: Note Reading in All Keys
In the Note Reading game, cycle through every key signature available. Spend 1-2 minutes in each key. Notice how the sharps/flats appear on the staff and which notes they affect.
Activity 2: Play Scales in New Keys
On the Synthesizer, play major scales in A major (3#), E major (4#), Ab major (4b), and Eb major (3b). Use the Circle of Fifths to figure out which notes are sharped or flatted.
Activity 3: Scale Ear Training — Intermediate
Move to Intermediate difficulty in Scale Identification. More scale types are added. See if you can still reliably identify major and minor while learning the new ones.
Activity 4: Scale Reading — Intermediate
Move to Intermediate difficulty in the Scale Reading game. Read scales across different key signatures on the staff. This reinforces your understanding of how key signatures shape the notes you see.