Recognize any key at a glance
Being able to name the key of a piece just by looking at the sharps or flats at the start of the staff (the key signature) saves a lot of guessing. Once you know the trick, you do not need to analyze a single note.
These exercises are built around two visual shortcuts that let you find the key in a fraction of a second. First, memorize the order in which accidentals always appear.
The fixed order of sharps and flats
Memorize these two sequences as one block each. They are the order in which accidentals are always written on the staff:
- Order of sharps (♯): F - C - G - D - A - E - B
- Order of flats (♭): B - E - A - D - G - C - F (exactly the reverse of the sharps)
1. The shortcut for key signatures with sharps
When the key signature has one or more sharps, the method is almost automatic:
- Look at the last sharp (the one farthest to the right, just before the music begins).
- Go up a half step (UK: semitone) from the name of that note.
- That note is the name of the major key.
Example: The key signature has three sharps (F♯, C♯, G♯). The last one is G♯. A half step above G♯ is A, so the key is A major.
2. The shortcut for key signatures with flats
With flats, the shortcut is even quicker, because you do not have to count any distance on the keyboard:
- Find the second-to-last flat in the key signature (the one just to the left of the last flat).
- That flat, with its own name, is the name of the major key.
Example: The key signature has four flats in this order (B♭, E♭, A♭, D♭). The second-to-last is A♭, so the key is A♭ major.
The one exception: this shortcut does not work with a single flat, because there is no second-to-last. A key signature with one flat (B♭) is always F major.
| Type of key signature | Shortcut for the major key | How to find the minor key (relative) |
|---|---|---|
| Sharps | Last sharp + a half step up = major tonic. | Go down a minor 3rd (3 half steps) from the major tonic. |
| Flats | The second-to-last flat is the major tonic (exception: one flat = F major). | Go down a minor 3rd (3 half steps) from the major tonic. |
Every major key has a relative minor key that shares the same notes and the same key signature but has a different character. Once you know the major key, go down a minor 3rd (a whole step plus a half step) to get the name of its relative minor.
The next step is to practice neighboring keys: finding out which keys can be reached easily by modulation.
Once you can recognize keys on paper, try recognizing them by ear. In the ear-training exercises recognize the major key, recognize the minor key and recognize the key (major and minor), you hear an A4 and then a melody, and you write its key with the same builder used in the neighboring keys exercise.
Playing scales with the online metronome builds muscle memory. The online tuner lets you check that the altered notes of each key signature are in tune.
If you need to review the theory first, read the pages on keys and key signatures and the circle of fifths.
Key signature worksheets to print (PDF)
The same two skills as above, on paper and with an answer sheet: one worksheet to identify the key of a written key signature and another to write the key signature of a key you are given. Each sheet has 21 exercises on a single side of A4, and everything goes from easier to harder:
- From few accidentals to many. They start with key signatures of one or two accidentals and end with those of six and seven.
- Treble clef first. The bass clef appears from the second third onward, once the mechanism has been picked up.
- Alternating major and minor. Each exercise says which of the two to give, so you have to go through the relative key.
Identify key signatures
The key signature is written out, and under it you note the key the exercise asks for: Major: or minor:.
Download the worksheet (A4 PDF) Answers
Write key signatures
The reverse exercise: you are given the name of the key (E♭ major, G minor…) and you draw its accidentals on the staff, in their order and in their place.
Download the worksheet (A4 PDF) Answers
You can print and photocopy them freely for the classroom. Each answer sheet is the same worksheet with the answers in red, so it can be marked by laying one over the other. If you need to review the theory first, see the page on keys and key signatures and the circle of fifths.