Normally, I'm really bad with key signatures. The thing is, I cannot memorize their names associated with their look. Is there an easy method/technique to recognizing the name of a key signature upon sight? For example, if I had a key signature that looked like this:

Key signature

How would I find that key signature's name?


3 Answers 3


The way I learned it, for flats you look at the second flat in the signature from the right. Here, it's A♭ (B♭-E♭-A♭-D♭).

For sharps, take the last sharp and raise it by a half-step. If you had F♯, C♯, and G♯ in the key signature, the last sharp is G♯. Up a half step from G♯ is A.

No sharps is C major, one flat is F major. You absolutely need to know those two by sight.

Note that this is for major keys. For minor, convert however you normally do from major. In this case, the minor key would be F minor.

I highly recommend that you devote some effort to being able to recognise key signatures on sight. You don't want to spend 30 seconds figuring out that you're playing in D major during a sight-reading gig (Actually, this skill sort of comes with practice itself, but certainly don't neglect it).

User Dom found this site, and it has a specific exercise for this. I really like this site, and I think you'll find this useful, especially if you want to memorise them: (The Exercise)

EDIT: If you need help with finding the minor key signatures, just find the major one (A♭), then find its sixth scale degree (A♭-B♭-C-D♭-E♭-F-G), et voilà, you know it's F minor. That, or memorization.

  • I have an alternative perspective: learn it in practice, instead of in theory. Practice is too underrated. ;) Apr 5, 2019 at 18:33
  • @piiperi Very true :)
    – user45266
    Apr 5, 2019 at 19:23
  • Of course, this supposes that it is major. Maybe the example is F minor.
    – badjohn
    Apr 6, 2019 at 7:29
  • 1
    @badjohn Aside from what I already had, here's some more explanation of the minor key signatures (in the edit)
    – user45266
    Apr 6, 2019 at 16:13
  • @user45266 Thanks. I didn't need it but maybe the OP did. By now, I just look and immediately say to myself: "A♭ major or F minor"; I am not sure how, it is just ingrained now.
    – badjohn
    Apr 6, 2019 at 16:51

What instrument do you play?

The way I learned it was not by memorizing, but by getting familiar with each key on the piano, playing songs by ear. At first I learned to play songs in C major or A minor, which is white keys only, no flats or sharps. Then I expanded to playing the songs in F major or D minor, which have one black key in their straight/natural form, B flattened to Bb. Then G major and E minor which have one sharp, F sharpened to F#. Then Bb major and G minor, which have two flats. Etc. In each one, the difference in the visual and fingering patterns was so unique, they were etched in my mind to the tonic notes of the respective major and minor keys. After playing a couple of songs in each key, it was impossible to forget how many sharps or flats there was.

So in other words, through practical exercise I learned to know all the basic aspects of each key as a "product package": where all the notes of the scale are, what are black and white keys, what the usual diatonic chords look and feel like when played in each key - and of course, how many sharps or flats this means. When I see a key signature, it's completely impossible not to know where the tonics of the major and minor keys are which use that key signature - because I've been in that key and experienced all the places and tricks first hand. Music is an exploration, not a guided tour.

I think my answer to this is the same as to most questions on this site: learn to play songs by ear as melody and chords. Do a set of both major and minor songs in all twelve key signatures, starting from C major / A minor and adding flats and sharps one by one. Do one key signature per week, and in three months you'll have improved your musicianship in ways you cannot imagine. Or if one per week is too fast, do one a month, and it'll take a year. This is hugely beneficial for just about anything you'll ever want to do in music.


Learn the musical alphabet in fifths ascending and descending.

Starting from C or A, fifths up add a sharp, and fifths down add a flat.

So, with 4 flats we start at C and go through the alphabet down in fifths: C, F, Bb, Eb, Ab. The major key is Ab major.

Starting at A go down in fifths: A, D, G, C, F. The minor key is F minor.

You can reverse directions and then subtract sharps or flats.

In time you will probably fix the key signatures in memory, and as you memorize some the others can be quick to 'calculate.' Eb minor is six flats. (I have that memorized, because it uses all the black keys on the piano.) I can go up a fifth and subtract a flat to get 5 flats for Bb minor.

Knowing the alphabet in fifths has more application that just knowing key signatures. It has important application in harmony. (It's also good to know the alphabet in thirds ascending/descending.)

Not the answer you're looking for? Browse other questions tagged or ask your own question.