Music Theory

Introduction The system of music notation allows us to specify two of the main characteristics of music: the note to be played, and its duration. The following pages will show the basic aspects of music reading. We will begin by learning how to specify durations of sound. For this, let’s take a look at two important concepts: beats (pulsations) and measures.

Beats and Measures We will use several examples to illustrate these two concepts. Beats – in each example you can hear a series of steady clicks, each one being a beat or a pulsation. Measures – the beats or pulsations are grouped in numbers of two, three and four. A measure is such a pattern of a group of beats. It is very common to find measures having groups of two, three or four beats.

Time Signature When reading music, the first element we will encounter at the beginning of the staff is the time signature. Measures are qualified by two numbers used in the time signature. The number on top indicates the amount of beats existing in each measure (we will later explain the function of the number on the bottom): 2 beats per measure 3 beats per measure 4 beats per measure

It is quite common to use the measure of

symbol as a time signature to define the

.

Note Value Once we understand the concept of measure and beats, we can start reading music. The duration of a sound is indicated using several symbols. Let’s start by getting to know the symbols with durations of one, two and four beats:

Name (USA)

Name (England)

Whole Note

Semibreve

4 beats

Half Note

Minim

2 beats

Quarter Note

Crotchet

1 beat

Duration Symbol

Note the relationship of values between the different symbols: Each whole note (semibreve): is divided into two half notes (minim). And each half note (minim) is divided into two quarter notes (crotchet) Thus, each symbol will have half the value of the preceding shape. Let’s see a musical example using these symbols. The vertical lines (or bar lines) separate and group the notes into measures in order to facilitate reading (we can see three measures in this particular example). You can hear a percussive sound for each beat, and a piano sound playing the written notes. Note how a half note will take the duration of two percussive sounds (two beats), the quarter note will take just one beat, and the whole note will take four beats:

Dotted Notes and the Tie We have already looked at symbols with durations of one, two and four beats, but what symbol can we use for a note having a duration of three beats? There is no symbol for such duration, but we can create one by adding a dot or a tie. Attaching a dot to the right side of the note will add half of its value to its total duration. For instance, if we add the dot to a half note (minim) - which normally lasts for two beats - we will then have a note lasting three beats instead of two (half of 2 is 1, and 2 + 1 = 3. Let’s now see the value of the shapes we already know, after adding the dot:

Note

Duration 6 beats (4 + 2) 3 beats (2 + 1) 1 beat and a half (1 + 1/2)

The tie allows us to achieve the same goal. Using a tie between two notes will add the value of the second note to the value of the first. For instance, if we tie a quarter note (crotchet) to a half note (minim) , we will get a note lasting three beats (same as a dotted half note). The following musical example illustrates the use of a dotted half note (minim), and a half note tied to a quarter note (crotchet). You will hear a percussive sound for each beat, and a piano sound playing the written notes. Note that the resulting rhythm on the first measure (using the tie) is exactly the same as the rhythm found on the second bar (using the dotted note).

Rests In music, silence is just as important as sound. How do we notate silence? We notate silence by using symbols called rest notes, or simply rests. There is an equivalent rest symbol for each note value. Below we can see the corresponding rest symbols for the note values we already know: Note Name Note Name Symbol Rest (USA) (England) Whole Note

Semibreve

Half Note

Minim

Quarter Note

Crotchet

Values Shorter Than a Beat The smallest value we have seen up to this point is that of the quarter note (crotchet), which lasts for a whole beat. Of course, there are symbols for notes of shorter duration.

Here you can see symbols that take a half (50%) or a fourth (25%) of a beat: Symbols

Name

Value

Eighth note (quaver)

Half of a quarter note. We can have two eighth notes for each beat.

Sixteenth note (semiquaver)

One fourth of a quarter note. We can have four of these for each beat.

It is common practice to beam together the flags of eight notes and sixteenth notes that are part of the same beat, in order to facilitate reading.

Eighth and Sixteenth Notes (quaver and semiquaver) There are many possible combinations of eight notes (quaver) and sixteenth notes (semiquaver) we can use. To make reading easier, it is necessary to learn to identify and comprehend these formulas of combinations. The following table shows some of the most common combinations. The small numbers given below the written notes indicate the subdivision in four equal parts of the beat:

Eighth-Note (quaver) and Sixteenth-Note (semiquaver) Rests There are also symbols to represent silence with the value of eighth notes (quaver) and sixteenth notes (semiquaver): Note

Rest

Eighth (quaver) Sixteenth (semiquaver) Following we can see a few examples using rests. The small numbers given below the written notes indicate the subdivision in four equal parts of the beat:

Triplets To this point, we have only subdivided each beat in two or four equal parts. However, it is also possible to divide a beat in three equal parts, with the use of triplets. Triplets are notated by writing the number 3 above the group of notes that will form the triplet. Note how, as in the second example, we can join two of the eight notes that are part of the triplet, forming a quarter note inside the triplet:

Beat Unit Until now, we have used the quarter note (crotchet) to represent the value of a beat. Nevertheless, we can indeed use any note value to serve as the beat unit. When the number four is on the bottom, we have seen that a quarter note (crotchet) gets one beat. In time signatures, the lower number indicates the kind of note that gets one beat, i.e., quarter note/crotchet (4), half note/minim (2), eighth note/quaver) (8), sixteenth/semiquaver note (16), etc. (see Time or Meter Signatures for more information). If we use 2 for the bottom number, the half note (minim) will then become the beat unit. We will now illustrate a series of rhythmic formulas written using the time signature of 2/2. Note that the half note (minim) now represents one beat, the quarter note (crotchet) is a half beat and the eight note (quaver) is a fourth of a beat.

Simple and Compound Meters The kinds of measures we have studied so far use what is known as simple meter. With simple meters, each beat is subdivided in equal halves. In the case of a 4/4 meter, each beat is divided into two eight notes, as we saw earlier. With compound meters, each beat is subdivided into three equal parts. We can tell a compound meter because it uses 6, 9 or 12 for the top number of the time signature. Let’s take a look at several examples of the compound meter of 6 over 8 (6/8). This meter actually has two beats; the note value that has the value of a beat is the dotted quarter note (crotchet), which can be subdivided into three eight notes (quaver).

Reading Musical Notes Now that we know how to read rhythms, how do we then write musical notes? The following animation will show you how to read them. Click on the question to begin: