To understand what a minor key is, we first need to look at what constitutes a major key. The easiest way to do this is to picture a piano keyboard:
The white notes above will play a C major scale (two octaves, actually). A major scale moves in steps like this: whole, whole, half, whole, whole, whole, half. When looking at the keyboard a whole step is constituted by moving over an extra note (in this scale all black notes), a half step does not have an extra note to move over. In the C major scale the notes are: C D E F G A B and back to C.
The minor key that corresponds with C major is A minor. To figure out which minor key corresponds to a major key, you count up to the sixth note, and begin from there.
Minor scales move in these steps: whole, half, whole, whole, half, whole – so A B C D E F G A. If you were to start on A in a major key it would go A B C# D E F# G# A. So the third, sixth, and seventh notes become depressed in a minor key.
In written music, C major and A minor have the same key signature: no sharps or flats listed. Like this:
The A major scale has a key signature like this:
The minor key that corresponds with A major is F# minor. The key of F# would normally have 6 sharps in it (a nightmare key to play in!), but in the minor key only has 3 sharps, because the third, sixth and seventh notes have once again been depressed a half note, making them naturals.
The word “depressed” is very apropos, because not only does it bring the note down a semi-tone, but it also makes the music sound melancholy. Whereas songs written in a major key sound upbeat and light, songs written in the minor seem somber and even dark at times.
The minor key gives us a whole new realm of music to listen to. And I, for one, would miss the emotional diversity without it.
