The_Complete_Idiot%27s_Guide_To_Music_Theory

Major and Minor Keys
In This Chapter
◆ Understanding major and minor keys
◆ Determining key by using key signatures
◆ Using the circle of fifths
◆ Applying accidentals and changing keys
4
Chapter
If you’re writing music within the C Major scale, you have it easy. All the notes
fall in the lines and spaces of the treble and bass clefs; no sharps or flats are necessary.
(And, if you’re playing the piano, you don’t have to use those tricky black
keys!)
However, if you’re writing music using another scale, you have to use accidentals
to raise and lower notes beyond the white keys on the piano keyboard. For
example, if you’re using the F Major scale, you have a pesky B-flat to deal with.
Now, you could put a flat sign in front of every B-flat in your music. However,
you’ll end up writing a lot of flats—which is a major pain in the butt.
Fortunately, there’s an easy way to designate consistent flats and sharps throughout
an entire piece of music, without noting each and every instance. This approach
requires the knowledge of musical keys—which just happen to correspond to the
musical scales we discussed in the previous chapter.
Keys to Success
When a piece of music is based on a particular musical scale, we say that music
is in the “key” of that scale. For example, a song based around the C Major
scale is in the key of C Major. A song based around the B-flat Major scale is in
the key of B-flat Major.
When you assign a key to a piece of music (or to a section within a larger piece),
it’s assumed that most of the notes in that music will stay within the corresponding
scale. So if a piece is written in A Major, most of the notes in the melody
and chords should be within the A Major scale. (There are exceptions to this, of
course; they’re called accidentals; they’re discussed later in this chapter.)