Here's the shortcut/trick I've always used to "read" key signatures. i.e., you know how many sharps or flats there are because they're all shown right there in the key signature...but rather than now polling & reverse-engineering your mental database of This Key Has This Many Accidentals, try this:
- For sharp keys, the key center is one half step higher than the last (right-most) sharp in the key signature.
E.g., you see four sharps in the key signature. You could either remember that the key of E has four sharps...or you could just look at that last sharp in the key signature and think "Oh, D#, so this tune is in the key of E."
- For flat keys, the key center is whatever the second-to-last flat in the key signature is.
E.g., you see four flats in the key signature. You could either remember that the key of Ab has four flats...or you could just look at that second-to-last flat in the key signature and think "Oh, Ab, so this tune is in the key of Ab."
Yeah, it feels a little like cheating.
- For sharp keys, the key center is one half step higher than the last (right-most) sharp in the key signature.
E.g., you see four sharps in the key signature. You could either remember that the key of E has four sharps...or you could just look at that last sharp in the key signature and think "Oh, D#, so this tune is in the key of E."
- For flat keys, the key center is whatever the second-to-last flat in the key signature is.
E.g., you see four flats in the key signature. You could either remember that the key of Ab has four flats...or you could just look at that second-to-last flat in the key signature and think "Oh, Ab, so this tune is in the key of Ab."
Yeah, it feels a little like cheating.


