Idiot's Guides - Music Theory
Page 7
The Intervals of the Locrian Mode
Note
Half Steps to Next Note
Tonic
1
Second
2
Third
2
Fourth
1
Fifth
2
Sixth
2
Seventh
2
B Locrian is relative to the key of C, and consists of the following notes:
B Locrian mode, relative to the key of C.
Exercises
Exercise 3-1
Name the following major scales.
Exercise 3-2
Name the following minor scales.
Exercise 3-3
Enter the notes for the following major scales.
Exercise 3-4
Enter the notes for the following minor scales.
Exercise 3-5
Name the natural minor scales related to the following major scales, and enter the notes for those scales.
Exercise 3-6
Enter the notes for the following modes, within the C Major scale.
The Least You Need to Know
A scale consists of eight notes whose letter names are in successive alphabetical order.
Scales can be either major or minor. (And there are three different types of minor scales!)
All major scales have the same intervals between different notes, no matter what note they start on.
A mode, like a scale, consists of eight notes in a row—but aren’t limited to just major and minor. Modes are derived from the ancient Greeks and (later) the medieval church, and can be thought of as starting on different degrees of the related major scale.
CHAPTER
4
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
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.)
Using Key Signatures
One of the convenient things about assigning a particular key to a piece of music is that it enables you to designate the appropriate sharps and flats up front, without having to repeat them every time they occur in the music.
Here’s how it works. You designate a key by inserting a key signature at the very start of the music, next to the first clef on the first staff. This key signature indicates the sharps and flats used in that particular key. Then, when you play through the entire piece, you automatically sharpen and flatten the appropriate notes.
For example, let’s say you write a song around the F Major scale. The F Major scale, if you recall, has one flatted note: B-flat. So next to the first clef on the first staff, you put a flat sign on the B line. Now, when you play that song, every time you see a B, you actually play B-flat.
The key signature for the key of F. (Note the flat sign on the B line, indicating the automatic B-flat.)
The same would apply if you were playing in the key of G, which has one sharp: F-sharp. You put a sharp sign on the top F line on the first staff; then every time you see an F, you play an F-sharp.
Determining the Key Signature
How can you quickly determine which key signature you’re looking at? It depends on whether the key signature contains sharps or flats.
If the key signature includes flats, the key (no pun intended) is to look at the next-to-last flat—the one next to the farthest one on the right. This note determines the key signature.
For example, if a key signature has two flats, you look at the next-to-last flat and determine that the key is B-flat, which it is. If the key signature has three flats, you look at the next-to-last flat, and determine that the key is E-flat. It’s pretty easy.
But what do you do if there’s only one flat? There’s no next-to-last flat! For the key signature with a single flat, the key is F. You’ll have to memorize that one, as you will the key with no flats or sharps—which is the key of C.
If the key signature includes sharps, the method is different. With sharps, know that the last sharp in the key signature represents the seventh degree of that particular scale, so the tonic of the scale is the next note up. In other words, look at the last sharp, and the next note up is the key.
Take, for example, the key signature with one sharp. That sharp is on the note F-sharp, so the next note up tells you that the key is G. If the key signature has two sharps, the last one is on the note C-sharp, and the next note up is D—which is your key. And so on for all the other sharp key signatures.
Major Keys
Just as there are 15 major scales (including three enharmonics), there are 15 major keys; each with its own key signature. The following table shows what each key of these key signatures looks like, along with its corresponding scale.
The 15 Major Keys
Key
Key Signature and Scale
C Major
C-sharp Major
D-flat Major
D Major
E-flat Major
E Major
F Major
F-sharp Major
G-flat Major
G Major
A-flat Major
A Major
B-flat Major
B Major
C-flat Major
Minor Keys
The key signatures used to indicate major keys also can represent natural minor keys. As you remember from Chapter 3, a natural minor scale is based on the same notes as a major scale, but starts on the sixth note of the scale. This same method applies to keys, so that (for example) the key of A minor uses the same notes—and the same key signature—as C major.
The following table shows the 15 minor keys, with their corresponding key signatures and scales.
The 15 Minor Keys
Scale
Notes
Same as This Major Key
A minor
C Major
A-sharp minor
C-sharp Major
B-flat minor
D-flat Major
B minor
D Major
C minor
E-flat Major
C-sharp minor
E Major
D minor
F Major
D-sharp minor
F-sharp Major
E-flat minor
G-flat Major
E minor
G Major
F minor
A-flat Major
F-sharp minor
A Major
G minor
B-flat Major
G-sharp minor
B Major
A-flat minor
C-flat Major
The Circle of Fifths
There’s a quick way to remember how many sharps or flats to include with each key signature; it’s called the circle of fifths, and it works like this.
Starting with the key of C, for every perfect fifth you move up, you add a sharp. So the key of G (a perfect fifth up from C) has one sharp. The key of D (a perfect fifth up from G) has two sharps, and so on.
The circle of fifths works in the other direction for flats. For every perfect fifth you move down from C, you add a flat. So the key of F (a perfect fifth down from C) has one flat. The key of B-flat (a perfect fifth down from F) has two flats, and so on.
The following drawing shows how all the major keys relate in the circle of fifths. When you move clockwise around the circle, you’re moving up through the fifths (and the sharp keys); when you move counterclockwise, you’re moving down through the fifths (and the flat keys).
All the major keys are a fifth apart in the circle of fifths.
The next figure shows the circle of fifths for the 15 minor keys. It works just the same as the major-key circle; move clockwise for the sharp keys, and counterclockwise for the flat keys.
The circle of fifths works for minor keys, too.
Accidents Will Happen
When you assign a key signature to a piece of music, it’s assumed that all the following notes will correspond to that particular key. How, then, do you indicate notes that fall outside that key?
First, note that you can play outside a key. For example, it’s okay to play the occasional B natural when you’re in the key of F, which normally has a B-flat. No one will arrest you for it—in fact, certain types of music regularly employ nonscale notes.
NOTE
Jazz and blues music often add flatted thirds and sevenths within the designated major key, which gives these styles their unique sound.
When you decide to write a note that isn’t within the current key, you have to manually indicate the change in the music—by using sharp, flat, or natural signs. When musicians see the inserted sharp, flat, or natural, they know to play the note as written, rather than as indicated by the music’s key signature.
These “outside the key” notes are called accidentals or chromatic notes; they’re quite common.
For example, let’s say a piece of music is in the key of F, which has only one flat (B-flat). You want your melody to include an E-flat, which isn’t in the key. So when you get to that note, you insert a flat sign before the E to indicate an E-flat. It’s as simple as that.
Use accidentals to indicate notes outside the current key signature.
WARNING
An accidental applies only from that point in the measure to the end of the measure. It doesn’t affect those notes in the measure before the accidental appears.
The same approach applies if you want to include a B natural in the same piece, instead of the expected B-flat. Simply insert a natural sign before the B.
When you change a note with an accidental, that accidental applies until the end of the current measure. At the start of the next measure, it’s assumed that all notes revert to what they should be in the current key. So if you flat an E in measure one of an F Major melody, the first E you write in measure two will be assumed to be natural, not flatted.
The one exception occurs when you tie a note from the end of one measure to the beginning of the next. The accidental carries over—thanks to the tie—to that first note in the second measure, as you can see in the following example. (Ties are explained in Chapter 5.) Note that the accidental doesn’t apply to any subsequent notes in the second measure; it applies only to the tied note.
Accidentals apply to all notes tied over a measure.
If you think other musicians might be confused about whether a note has reverted back to normal, it’s okay to use a courtesy sharp, flat, or natural sign. (This is a sign placed within parentheses.) This reminds the reader that the note has reverted back to its normal state in that key. You don’t have to use courtesy signs, but when the music is complicated, it can be helpful.
A courtesy accidental reminds musicians that a changed note has reverted back to normal.
Changing Keys
Some long pieces of music don’t always use the same key throughout the entire piece. In fact, some short pop songs change keys midway through. It’s allowed.
When you change keys in the middle of a song, it’s called modulating to another key. You can modulate to any key, although the most common modulations are up a half step (from E Major to F Major, for example), or up a fourth or fifth (from E Major to either A Major or B Major, for example).
TIP
The half-step modulation is most common in twentieth-century popular music, and can add a “lift” to the end of a pop song. The fourth or fifth modulation is more common in classical music of the seventeenth through the nineteenth centuries.
When you want to change keys, you indicate this by inserting a new key signature in the first measure of the new key. It’s as simple as that, as you can see in the following figure. (Note that some composers and arrangers also insert a double bar whenever there’s a key change.)
To change keys, insert a new key signature.
TIP
If you want, you can alert musicians to a key change by placing the appropriate sharps and flats at the very end of the last staff of the old key—as well as with a new key signature in the following measure. This approach is entirely optional; it’s perfectly acceptable to signal the key change with a single key signature in the first measure of the new key.
The only complicated key change is when you’re changing to the key of C—which has no sharps or flats. You indicate this by using natural signs to cancel out the previous sharps or flats, like this:
How to change to the key of C.
Exercises
Exercise 4-1
Label the following major key signatures.
Exercise 4-2
Label the following minor key signatures.
Exercise 4-3
Create the indicated major key signatures.
Exercise 4-4
Create the indicated minor key signatures.
Exercise 4-5
Using the initial key signature as a guide, label each note in the following example.
Exercise 4-6
Determine what key signature you could use to write this melody without accidentals, and enter that key signature at the beginning of the staff.
Exercise 4-7
Determine what key signature you could use to write this melody without accidentals, and enter that key signature at the beginning of the staff.
Exercise 4-8
Following the circle of fifths, add the appropriate number of flats to each successive major key signature, and then label each key signature.
The Least You Need to Know
You use key signatures to indicate what scale your music is based on.
The sharps and flats in a key signature are automatically applied throughout the entire song.
To indicate notes outside the current key, use accidentals—sharps, flats, and natural signs.
To change the key in the middle of a piece of music, insert a new key signature.
PART
2
Rhythms
You don’t have to be a drummer to feel the beat. This part shows you how to notate any type of rhythm, from simple whole notes to sixteenth note syncopations. You also learn all about time signatures, tempo, and dynamics as well as how to navigate your way through a piece of music.
CHAPTER
5
Note Values and Basic Notation
In This Chapter
Grouping beats into measures
Understanding whole, half, quarter, eighth, and sixteenth notes and rests
Using dotted notes and ties
Dividing beats into triplets
Lesson 4, Track 27
Part 1 of this book covered how to work with pitch—but that’s only half of the music theory that you need to know. In this chapter, we’ll deal with the other half of the equation, which is how you work with time—which, in music, is called rhythm.