Understanding Key Signatures in Songs and Pieces

Teach Students to Identify Which Keys Contain Which Flats and Sharps

Oct 2, 2011
Karen Berger

Scales tell musicians which chords and notes work together. - Karen Berger

Scales are the building blocks of music. Understanding them improves technique. Scales also tell musicians which chords and notes sound good together.

There are 12 major scales in the western music system, along with 12 related minor scales. Each of these scales has it's own set of notes, including sharp notes and flat notes. Knowing which notes go in which scale, and how many sharps and flats each scale has, is a basic skill that music students must master. Indeed, being fluent in scales is not only an issue of technique and theory, but gives students the basic building blocks they need to improvise and have fun with all kinds of music, including pop and jazz.

Understanding Sharp Keys

Sharps are written like a little tic-tac-toe board (#). To find the key signature, go to the very beginning of the piece. The sharps are written in a row. To figure out which key the song is in, go to the very last sharp (the one on the far right of the row of sharps). Then simply go up to the very next note. For example, if the last sharp is a C#, the song is in D; if it is a G#, the song is in A.

Note that this only works for what we call major keys. If the song sounds sad or dark, it is probably written in a minor key. To find which minor key you are playing in, first identify the major key, then go down one and a half steps (or three half steps, if you prefer) to find the minor. (Going down a "half step" simply means to go down to the very next note, regardless of whether it is a black note or a white note.)

If this sounds confusing, don't worry; you'll get the hang of it with practice. In the meantime, or for those who prefer memorization, here is a list of the keys and their sharps and flats.

Key of G or Em has one sharp: F
Key of D or Bm has two sharps: F and C
Key of A or F#m has three sharps: F,C, and G
Key of E or C#m has four sharps: F,C, G, and D
Key of B or G#m has five sharps: F, C, G, D, and A
Key of F# or D#m has six sharps: F,C,G,D, A, and E
Key of C# or A#m has seven sharps: F. C.G. D, A, E, and B

As is obvious, the sharps occur in a regular pattern: Each subsequent key keeps all the sharps before and adds the one just before the name of the new key. By understanding these patterns, the process of memorizing this information becomes much easier.

Understanding Flat Keys

Flats are written like a small italized letter "b" (b). To find the (major) key signature, go to the very beginning of the piece where the flats are written in a row. To figure out which key the song is in, go to the second flat from the right (the second to last flat) That is the (major) key signature. Note that this doesn't work in the key of F, because F only has one flat. (It's a B flat). This simply has to be remembered on its own.

Here is a list of the flat keys.

Key of F or Dm has one flat: B
Key of Bb or Gm has two flats: B and E
Key of EbA or Cm has three flats: B, E, and A
Key of Ab or Fm has four flats: B, E, A, and D
Key of Db or Bbm has five flats: B, E, A, D, and G
Key of Gb or Ebm has five flats: B, E, A, D, G, and C
Key of Cbm or Abm B, E, A, D, G, C, and F

Note that the lists above have omitted one very important key: The key of C major (it's relative minor is A minor). C major has zero sharps and zero flats. As such, it is the first key many music students encounter.

A final note: The last three keys in each list can be very confusing to beginning players, who probably

won't encounter them for quite a while, and on some instruments, may not encounter them at all. So consider their inclusion here a matter of information to use when and if it is needed, and concentrate instead on the easier keys, with up to four sharps or flats.