Key Signatures
Sharps or flats stated right after the clef are called key signatures. Every key signature has its own name. The sharps or flats in the key signature affect all of the notes of the same letter name in the music. For example, a flat written on the B line in the key signature means that all B’s should be played as Bb’s.
Note! The most common key signatures in beginning ensembles are:
| Instrument | Most Common Key Signatures |
C instruments: flute, oboe, bassoon, trombone, baritone, tuba, mallets, timpani, piano, violin, cello, bass, guitar |
F, Bb, Eb, and Ab |
Bb instruments: clarinet, trumpet, tenor saxophone |
G, C, F, and Bb |
Eb instruments: alto and baritone saxophone |
D, G, C, and F |
F instruments: French horn |
C, F, Bb, and Eb |
Flats
The order of flats in a key signature is always the same: B E A D G C F. The acronym to assist in learning this is B E A D Greatest Common Factor.
Hover your mouse over the example to see the order.
The key for a piece of music can be determined by its key signature. If the key signature is comprised of flats, then the 2nd to last flat is the key of the piece. For example, if there are 3 flats (Bb, Eb, and Ab), the Eb is the 2nd to last flat, and therefore, the key of the piece. In doing this, we also learn that the key of Concert Eb has 3 flats. If there is only 1 flat (Bb), then the key is Concert F Major. If there are no flats or sharps, then the key is Concert C Major.
Sharps
The order of sharps in a key signature is always the same: F C G D A E B. The acronym to assist in learning this is Fat Cats Go Down Alleys Eating Birds.
Hover your mouse over the example to see the order.
Do you notice the relationship between the order of sharps and the order of flats? They are an exact reverse of each other!
If the key signature is comprised of sharps, then the note above the last sharp is the key of the piece. For example, if there are 3 sharps (F#, C#, and G#), the note above the G# is an A, and therefore the key of the piece. We learn that the key of Concert A has 3 sharps.
