Idiot's Guides - Music Theory Page 9
However, not all music has four beats per measure, and not every beat is equal to a quarter note. To understand all the different numbers and types of beats per measure, you need only apply a little math—in the form of fractions.
Measuring the Beats
Written music uses something called a time signature to signify how many beats are in a measure and what kind of note is used for the basic beat. A time signature looks kind of like a fraction, with one number sitting on top of another number. The top number indicates how many beats are in a measure; the bottom number indicates the note value of the basic beat.
Time signatures show how beats are organized in a particular piece of music. This organization is called meter, and time signatures are sometimes called meter signatures.
NOTE
Classical musicians tend to refer to the organization of beats as “meter,” while jazz and pop musicians tend to refer to it as “time,” as in “4/4 meter” or “4/4 time.”
Let’s take the four-quarter-notes-to-a-measure form we used in the previous chapter. Because we have four beats in a measure, the top number in the time signature is a four. Because the basic beat is a quarter note, the bottom number is a four (as in the 4 in ¼). So the standard form we’ve been using is called “four four” time (because of the 4 on top of the 4), and looks like this:
The time signature for 4/4 meter.
Other time signatures follow this same form. For example, if our measures have three beats instead of four, and still use a quarter note for the beat, we have a 3/4 time signature. If you have three beats per measure but the basic beat is an eighth note instead of a quarter note, that time signature is “three eight,” or 3/8.
Read on to learn more about the different types of time signatures you’re likely to encounter in the world of music.
Quarter-Note Time
The most common types of time signatures use a quarter note for the base beat. However, you’re not limited to just four beats (quarter notes) per measure; quarter-note time signatures can have as few as one beat per measure, or as many as … well, as many as you like!
Although 4/4 is the most common quarter-note time signature, you’ll almost definitely run into its close cousin, 3/4. In 3/4 time, you have three quarter notes per measure; the measures are counted “one, two, three; one, two, three.” If you’ve ever heard a waltz, you’ve heard 3/4 time.
NOTE
In most rock and pop music, the second and fourth beats of a measure are accented, typically by the drummer, like this: one, TWO, three, FOUR; one, TWO, three, FOUR. (When you clap your hands to a song, you’re probably clapping on two and four.) This heavy “backbeat” is what gives rock and roll its rolling rhythm; it is so common that it’s noticeable when it is absent.
Another common quarter-note time signature is 2/4 time. This time signature is common in marches and other fast music, and is very easy to play. After all, two measures of 2/4 add up to one measure of 4/4!
Less common are quarter-note time signatures with more than four beats per measure. For example, 5/4 time feels a little awkward, especially if you’re used to feeling the “backbeat” in a 4/4 pop song. But jazz musicians play a lot of 5/4—just listen to the Dave Brubeck Quartet’s famous recording of “Take Five” if you want to hear a good example of playing in five.
The following table shows some of the more common quarter-note time signatures.
Quarter-Note Time Signatures
Time Signature
Beats per Measure
By the way, 4/4 time is sometimes called common time, and indicated by a large “C” for the time signature, like this:
4/4 time is common time—indicated by a big “C.”
Eighth-Note Time
Not all music uses a quarter note for the beat. A lot of music—especially classical music—is based on an eighth-note beat.
When you have an eighth-note time signature, such as 3/8 or 6/8, every time you tap your foot you’re tapping an eighth note, not a quarter note. So for a measure of 3/8, you’d tap three eighth notes; for a measure of 6/8, you’d tap six eighth notes.
When the eighth note is the beat, half a beat (the “and” after the beat, if you’re counting) will be a sixteenth note. Also, if you see a quarter note in an eighth-note time signature, that note takes up two beats.
It’s all about math, basically. When you play in an eighth-note time signature, all your normal note values take up half as much space as they do in a quarter-note time signature. It’s simple division.
The most common eighth-note time signatures are those divisible by three: 3/8, 6/8, 9/8, and so on. When you’re playing one of these time signatures and you’re playing really fast, you might end up tapping your foot just once every three beats, like this: ONE, two, three, FOUR, five, six; ONE, two, three, FOUR, five, six. (In fact, many conductors will conduct 6/8 time with just two downbeats per measure—the one and the four.) These time signatures sound a lot like 3/4, the waltz time signature. The following table details the most common eighth-note time signatures.
WARNING
Don’t assume that an eighth-note time signature is automatically twice as fast as a quarter-note time signature. Although this might be true (and almost always is true when time signatures change in the middle of a song), the speed of the beat (what musicians call tempo) is independent of the time signature. Thus, a song in 3/8 time actually could be played slower than a song in 3/4. (Learn more about tempo in Chapter 7.)
Eighth-Note Time Signatures
Time Signature
Beats per Measure
Half Time
If you move the other direction from the basic quarter-note time signature, you get into time signatures based on a half-note beat. In a half-note time signature, each half note gets one beat; quarter notes get half a beat, and eighth notes get a quarter of a beat. Whole notes, on the other hand, get just two beats. (It’s not really that confusing; it’s just more math to deal with.)
Half-note beats—2/2, 3/2, and the like—are typically used in classical music for slower, more sweeping passages.
The following table presents the most common half-note beats.
Half-Note Time Signatures
Time Signature
Beats per Measure
Just as 4/4 is sometimes called common time, 2/2 is sometimes called cut time. You can indicate 2/2 by either the normal time signature, or by a large C with a line through it, like this:
2/2 time is cut-time—thus you cut a “C” in half.
Changing the Time
You always indicate the time signature at the very beginning of a piece of music. However, you don’t have to keep the same time signature through the entire song; you can change time anywhere you want in a piece of music, even for just a measure or two!
If the meter changes in the middle of a song, you insert a new time signature at the point of change. This new time signature remains in effect through the rest of the song, or until another new time signature is introduced.
TIP
In most music notation, the time signature is shown only on the first line of music (or when there’s a time change)—unlike the key signature, which is typically shown at the start of each line.
Here’s what a time change looks like in the middle of a piece of music:
Changing time signatures in the middle of a song.
Grouping the Beats
If you see a piece of music in 9/8 and despair about counting that high (nine’s a lot higher than four), there’s a way around the problem. You can do as many musicians do: chop up each measure into smaller groupings.
When you’re playing in odd time signatures—especially those with more than four beats per measure—it’s common to subdivide the beats within a measure into an easier-to-grasp pattern. Using smaller groupings not only makes each measure easier to count; it also makes the music flow better. When you subdivide measures in this fashion, you create sub-rhythms behind the basic beat, which makes the music
easier to listen to.
For example, if you’re playing in 6/8 time, you could count all the beats evenly (one, two, three, four, five, six)—or you could subdivide the beat. The most common subdivision of 6/8 divides the measure into two equal parts, each containing three beats, like this:
Subdividing a 6/8 measure into two groups of three.
So you count the measure “one, two, three; one, two, three” or “one, two, three; two, two, three.” Easier, isn’t it?
Of course, you could also divide 6/8 into three groups of two, or one group of four and one group of two, or one group of one and one group of five, but the two groups of three is the most common way to play this particular time signature.
For another example, let’s look at 5/4 time. In 5/4, measures are typically sub-divided into one group of three and one group of two, like this:
Subdividing 5/4 time into one group of three and one group of two.
You count each measure “one, two, three; one, two.”
Of course, you could also reverse the groupings, and end up with two beats in the first group and three beats in the second—”one, two; one, two, three.” It depends on the feel and the flow of the music.
The more beats you have in a measure, the more possible groupings you can come up with. To demonstrate, the following example shows three possible groupings of 7/4 time: 4+3, 3+4, and 2+3+2.
Three different ways to group 7/4 time.
Just for fun, count all the way up to 11, and see how many groupings you can come up with for a measure of 11/4!
Exercises
Exercise 6-1
Write the following time signatures on the staff.
Exercise 6-2
Enter the appropriate number of quarter notes per measure for each time signature.
Exercise 6-3
Enter the appropriate number of eighth notes for each time signature.
Exercise 6-4
Enter the equivalent eighth-note time signature for each quarter-note time signature.
Exercise 6-5
Enter the equivalent quarter-note time signature for each half-note time signature.
Exercise 6-6
Enter bar lines to divide the following piece of music into four measures of 3/4 time.
Exercise 6-7
Enter bar lines to divide the following piece of music into four measures of 7/8 time.
Exercise 6-8
Group the beats in the following measures three different ways each.
The Least You Need to Know
You have to place a time signature at the beginning of a piece of music—or anywhere you change the basic meter or time.
The top number in a time signature indicates the number of beats per measure.
The bottom number in a time signature indicates what note is used for the basic beat.
Odd time signatures are sometimes broken up into smaller groupings, to make each measure easier to count.
CHAPTER
7
Tempo, Dynamics, and Navigation
In This Chapter
Determining how fast to play
Changing tempo
Determining how loud to play
Changing dynamics and accenting notes
Repeating parts of a song
You might not have noticed, but the first six chapters of this book taught you how to read and write music. That’s right—all those bits about staves, clefs, notes, and rests comprise what we call the standard music notation, which is the common language of all musicians.
Think of it this way: the staff, clef, and key signature determine where a note is in terms of pitch. The time signature and note value determine where a note is in terms of time, or rhythm. By placing a note in this two-dimensional space, you tell a musician everything he or she needs to know to play that note—and all the notes that follow.
The only things you haven’t yet learned about music notation are how to signify the speed (tempo) and loudness (dynamics) of a piece of music. We look at both topics in this chapter, along with some simple navigational aids to help you get from one point to another within a song.
Taking the Pulse
In Chapter 6 you learned how to figure out how many beats there are in a measure. The question remains, however, how fast those beats should be played.
The speed of a piece of music—how fast the beat goes by—is called the tempo. A faster tempo means a faster beat; a slower tempo makes for a slower song.
You can indicate tempo in one of two ways: by indicating the precise number of beats per minute or by using traditional Italian terms. We’ll discuss both methods next.
NOTE
As you’ll soon see, many notation markings (especially for classical music) are in Italian. This speaks to the importance of Italian culture in the evolution of Western music, but it also means it wouldn’t be a bad thing to know a little Italian—and I don’t mean a short guy named Mario!
Beats per Minute
The most accurate way to indicate tempo is by specifying a certain number of beats per minute, or bpm. This gives you a very precise speed for your song, especially when you use a metronome or a click track on a computer or in a recording studio. You set your metronome or click to a specific bpm number, and it tick-tocks back and forth at the proper speed. When you play along to the metronome or click track, you’re playing at exactly the right tempo.
Setting the tempo—120 quarter-note beats per minute.
DEFINITION
A metronome is a device (invented by a contemporary of Beethoven named Maelzel; in classical music, the abbreviation MM, for Maelzel’s Metronome, is used to represent beats per minute) that precisely ticks off beat after beat at a specified tempo. Metronomes can be either pendulum-type affairs or computerized devices that emit an electronic beat. When you’re playing professionally (especially in recording studios), you might run into a click track, a type of electronic metronome. The click track is typically played on a synthesized instrument, like an electronic woodblock or cowbell. (To hear what a click track sounds like, listen to the rhythm and melody exercises provided online; I use a click to “count off” each of the exercises.)
Italian Tempo Terms
The second way to indicate tempo, typically found in orchestral music, is through the use of traditional Italian musical terms. These terms correspond to general tempo ranges, as indicated in the following table, which is arranged from the very slowest to the very fastest tempo.
Italian Tempo Terms
Tempo
Means …
Slow Tempos (40–75 bpm)
grave
Very slow; solemn
largo
Slow and dignified
larghetto
A little faster than largo
lento
Slow
adagio
Moderately slow
adagietto
A little faster than adagio
Moderate Tempos (70–115 bpm)
andante
A “walking” tempo
andantino
A little faster than andante
moderato
Moderate pace
allegretto
Not quite as fast as allegro
Fast Tempos (110–220 bpm)
allegro
Fast, cheerful
vivace
Lively
presto
Very fast
prestissimo
Very, very fast
TIP
Sometimes you’ll see these tempo terms accompanied by the word “molto,” which means “very.” So if you see molto vivace, you know that the music should be played “very lively.”
These tempo markings are very approximate, and even the order is not always 100 percent observed. The important thing the Italian terms try to get across is the “spirit” of the music. For example, the word “allegro” in Italian really means “cheerful.” When these markings are used, the precise tempo is always left to the dis
cretion of the orchestra’s conductor.
So when you see a piece of music marked “Allegro,” such as Bach’s Brandenburg Concerto No. 6, you know that it should be played fairly fast. If you see a piece marked “Largo,” like the second movement of Dvořák’s New World Symphony, you know that the tempo should be fairly slow. This method isn’t terribly precise, but it will get you in the ballpark.
Specifying tempo using traditional Italian terms. (Play this one fast!)
Speeding Up—and Slowing Down
Some pieces of music retain the same tempo throughout the entire song (think most popular music here). Other pieces of music speed up and slow down at times, often for dramatic effect.
If a tempo change is immediate—that is, you go directly from one tempo to another, with no gradual transition—you indicate the change by inserting a new tempo marking of your choice. For example, if you’ve been playing at 120 bpm and want to switch to a faster tempo—160 bpm, let’s say—all you have to do is insert a new 160 bpm tempo mark. If you’re using Italian tempo markings, just insert the new marking where you want the tempo to change.