Key Signatures
Music can be written in many different keys, or tonal centers. You may recall from the solfege chapter that a tonal center, or “Do”, is like home base – the music is organized around it.
Every key is made up of its own unique combination of notes, often including sharps and flats. Some keys have just a few sharps or flats, and some keys have a lot. For instance, here is the well-known song “Yankee Doodle” written in the key of C – in other words, C is “Do.”
Notice that it has no sharps or flats.
Here is the same song written in a new tonal center: this time, F is “Do.”
See how it has a flat note in the melody? That’s B flat. It always appears in the key of F.
Why do we need key signatures?
Now, let's see what the song looks like when it starts on a B.
Wow … that’s a lot of sharps, isn’t it? Doesn’t it look a little cluttered with all those sharps all over the staff?
This is why we have key signatures. Instead of writing in all of those sharp and flat signs every time they occur, we put them all at the beginning of each line of music. Here’s “Yankee Doodle” in B once again – but this time, we’re using a key signature to clean it up:
Circle of Fifths
Every key has its own unique key signature. Musicians must memorize all of these key signatures to play in all of the keys. Fortunately for those who are just starting to learn their key signatures, there is a handy chart to help you remember them. It’s called the Circle of Fifths.
