Have you ever wondered what those strange symbols are at the very beginning of each line of music?

Doesn’t it seem a little bit pointless to have them at the beginning of each line? Those symbols are sharps or flats and the collection of those sharps and flats at the beginning of every line is called the key signature.
Have you ever looked a piece of music and noticed that although there are sharp notes and flat notes in nearly every piece of music, you don’t see a lot of them written? Once you get beyond the sharps and flats on the extreme left hand side of the line, they aren’t written in the music so how do musicians know to play certain notes as sharp or flat?

That’s where the key signature comes in.

Here are four rules to remember when learning about key signature:

• A key signature cannot have a mixture of sharps and flats. It has to be one or the other or none at all.

• The sharps and flats are always written in the same order.

• Just because a note is in the key signature doesn’t necessarily mean that you will find it in the actual music.

• If the key signature says that a note is sharp or flat, any note, regardless of octave, will be changed. So if the key signature shows an F#, high F’s, low F’s, or any other F is sharp.

Before we learn how to use the key signature, memorize the order of sharps and the order of flats. The order of the sharps is F,C,G,D,A,E,B. The order of flats is the order of sharps backwards: B,E,A,D,G,C,F. What is this? This is the order, left to right, that the sharps or flats will placed in the key signature.

Now that you have memorized your order of sharps or flats, look at rule #2 above. The sharps and flats are always written in the same order. Let’s say that your key signature has two sharps. You can squint your eyes and look at what lines or spaces those sharps are on or you can remember your order of sharps. If there are two sharps, look at the first two sharps in your order, F and C. This means that every time you come across an F or C in the music, you play them as F# or C#. It’s that easy.

If your key signature has 4 flats, recall the first four flats in your order of flats: B,E,A,D. All of these notes are flat if you have to play them in the music.

What if there are no flats or sharps in the key signature?

That’s not a misprint. That’s allowed as well. This means that all of the notes are natural (white keys on a piano or keyboard) in the piece of music you are about to play unless the composer adds a sharp or flat to a single note in the music.

Make sense? Next time you play a piece of music, take a look at the key signature even if you only read chord symbols or tabs. Knowing which notes are flat can help you decipher some of those complicated chord symbols.