Relative Minor Keys
Up to this point, you have learned solely about major key signatures and their related major scales — the circle of keys and those two tricks for naming the keys have all referred to major keys.
Of course, you know about minor scales, and where there are scales, there are keys. The good news is that all of the minor scales and keys share the same key signatures, which you already know. The bad news is that they aren't the same as the major keys! Never fear, there are some easy ways for you to learn the minor keys as well.
Every major key and its corresponding key signature has a dual function. Not only does it indicate a major key, but it also indicates one minor key as well. The concept is called relative keys and related minor. Simply put, every major scale/key has a minor scale/key hiding inside it. For now, you'll learn how to figure out the name of the minor keys. FIGURE 5.6 shows the key signature for Eb major. The exact same key signature can also signify the key of C minor.
How is this possible? Well, simply put, you could spell the Eb major scale and the C minor scale and see that they share the exact same key signature! The other thing that you are seeing is something called a mode. If you've never heard of modes before, you just learned your first one: The minor scale is a mode of the major scale. Modes come up in the next chapter, so hold tight, but for now, just understand that since they share the same pitches, and even if they are in a different order, they are related.
Point to Consider
Just looking at a key signature won't tell you whether your piece is in the major or the minor key. To find out for sure, you need to investigate the piece itself, not just the signature.
To name a minor key signature, first name the major key. Once you have found that, you simply count up six notes (up a major sixth) or down three (down a minor third). Either way, you arrive at the same note. In the case of C major, counting up six notes brings you to the note A. C major and A minor share the same key signature. They are referred to as “related keys.” When you look at a piece with no sharps or flats in the signature, it may not necessarily be in C major, it could just as easily be in A minor. You won't know for sure by just looking at a key signature because music simply isn't that easy. To really get the answer, you have to look at the harmony of the piece, and harmony and chords come later in this book. For now, just work on being able to name minor keys from major key signatures.
When naming a minor key, be careful to look at the key signature when you are doing so. Simply counting up six notes or down three notes may not give you the correct key. If the note you pick has a sharp or a flat in that key, the name of the minor key needs to reflect that. Simply, you're not just counting up six letters; you have to mind the key signature. It's much easier to use the interval of a major sixth, which has a clear name! Look at FIGURE 5.7. In this case, the sixth note was not just C, but C#, so the name of the key had to reflect that. The key of E major has a relative minor of C# minor.
FIGURE 5.8 is the full circle of keys with both the major and the minor keys listed.
We know that you can determine the key by looking at the signature and checking your circle of keys. Doing so will give you at least two answers: the major and the relative minor key. In a way, this is your first step toward musical analysis. But musical analysis is more than just looking at a key signature. The answer is rarely that simple. Or isn't it?
An old trick exists that suggests that you can look at the first and last notes of any piece to determine the key of a piece. Now, this rarely works, because music involves so many variables, but sometimes it does work. If you look at a key signature and your choices are either a minor or a major key (C major or A minor, for example), you could scan the piece for Cs or As and that may answer your question. Then again, it may not. While it is true that many pieces conclude on the tonic note of the key, that really gives you only the answer of where the piece ended and ignores the question of where it went in the middle.
Composer Antonio Vivaldi was born in Venice on March 4, 1678, and died in Vienna on July 28, 1741. He was the son of a professional violinist, and was also an accomplished violinist himself. Ordained as a priest in 1703, he soon stopped celebrating Mass on account of his poor health. Today Vivaldi is most famous for his work Le Quattro Stagioni (The Four Seasons).
Simply put, if you are trying to decipher what key you're in, the first and last note (or chord) may give you a basic answer. The only true answer that works in every piece can be found only by looking at the details of the piece — and that involves looking at not only the key signature, but also the harmony and per-note changes that exist throughout the piece. Since you know about scales in detail now, you can work on one more aspect of keys based on minor scales and their typical visual patterns.