Rhythm
Rhythm is the way audible music is organized in time, while beat is the steady pulse that underlies most music. Sometimes the beat is audible, sometimes not, but it is present, like the silent or ticking second-hand on a mechanical clock.
Tempo
The speed of the beat is called the tempo. Occasionally, the beat slows or pauses. Table 2 shows different tempos and their traditional Italian names. The Italian terms predate the invention of exact timekeeping, so they originally indicated mood or other expressive qualities as related to tempo. For example, Allegro means “cheerful,” and so the music should be executed in a fairly lively, or slightly “fast” manner. The numbers at the left indicate the approximate number of beats per minute. Substantial variations exist in the beats-per-minute. Tempo can slow down (ritardando) or speed up (accelerando), and it can do either gradually (poco a poco) or suddenly (subito). When there is no steady tempo—which is the same as no discernible beat—music is said to be unmetered; if there is a perceived beat, but it speeds up and slows down for expressive effect, it is called rubato.
Rhythm is the way audible music is organized in time, while beat is the steady pulse that underlies most music. Sometimes the beat is audible, sometimes not, but it is present, like the silent or ticking second-hand on a mechanical clock.
Tempo
The speed of the beat is called the tempo. Occasionally, the beat slows or pauses. Table 2 shows different tempos and their traditional Italian names. The Italian terms predate the invention of exact timekeeping, so they originally indicated mood or other expressive qualities as related to tempo. For example, Allegro means “cheerful,” and so the music should be executed in a fairly lively, or slightly “fast” manner. The numbers at the left indicate the approximate number of beats per minute. Substantial variations exist in the beats-per-minute. Tempo can slow down (ritardando) or speed up (accelerando), and it can do either gradually (poco a poco) or suddenly (subito). When there is no steady tempo—which is the same as no discernible beat—music is said to be unmetered; if there is a perceived beat, but it speeds up and slows down for expressive effect, it is called rubato.
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Rhythmic Notation
There are several symbols that indicate how long a note should last. An oval note, called a whole note, is the longest symbol used today. A line called a stem can be added to that oval, and that oval-plus-stem symbol indicates a time value that is half as long as the whole note, or a half note. When the oval, or note head, is solid black (with a stem), that indicates a quarter note: a note that is half as long as a half note (and one-fourth the duration of a whole note). When a flag is added to the stem, the quarter note is halved in duration, so that is called an eighth note. Additional flags can be added, each subdividing the value of the note by half again: sixteenth notes, thirty-second notes, and so forth. The relationships of the most common note symbols are shown in Figure 4. Notice that multiple flagged notes have an alternate notation, called beams; these are sometimes easier for a musician to read quickly, since it is customary to “beam” together a beat’s worth of notes.
Another device used in rhythmic notation is the dot. A dot adds half the original value to a note—so a dot following a half note would represent a quarter note, and thus the total duration of a dotted half note should be a half note plus a quarter note. Also, notes of the same pitch can be connected with a curved line called a tie; it “ties” their values together, so that the note lasts as long as their combined values.
The note value symbols in the top half of Figure 4 indicate how long musical sounds should last—but musicians can also be told how long not to make sound. These symbols for silence are called rests, and they follow a similar hierarchy as the note values; the lower half of Figure 4 illustrates the standard rest symbols (and their equivalent note symbols), and how each rest should be placed on a staff. The placement is especially important for whole rests and half rests; they look identical otherwise.
There are several symbols that indicate how long a note should last. An oval note, called a whole note, is the longest symbol used today. A line called a stem can be added to that oval, and that oval-plus-stem symbol indicates a time value that is half as long as the whole note, or a half note. When the oval, or note head, is solid black (with a stem), that indicates a quarter note: a note that is half as long as a half note (and one-fourth the duration of a whole note). When a flag is added to the stem, the quarter note is halved in duration, so that is called an eighth note. Additional flags can be added, each subdividing the value of the note by half again: sixteenth notes, thirty-second notes, and so forth. The relationships of the most common note symbols are shown in Figure 4. Notice that multiple flagged notes have an alternate notation, called beams; these are sometimes easier for a musician to read quickly, since it is customary to “beam” together a beat’s worth of notes.
Another device used in rhythmic notation is the dot. A dot adds half the original value to a note—so a dot following a half note would represent a quarter note, and thus the total duration of a dotted half note should be a half note plus a quarter note. Also, notes of the same pitch can be connected with a curved line called a tie; it “ties” their values together, so that the note lasts as long as their combined values.
The note value symbols in the top half of Figure 4 indicate how long musical sounds should last—but musicians can also be told how long not to make sound. These symbols for silence are called rests, and they follow a similar hierarchy as the note values; the lower half of Figure 4 illustrates the standard rest symbols (and their equivalent note symbols), and how each rest should be placed on a staff. The placement is especially important for whole rests and half rests; they look identical otherwise.
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Syncopation
Rhythm is syncopated when accented or emphasized notes fall on weak beats, or in between beats. The rhythms in “Happy Birthday” are regular and coincide with the beat, so it is not considered syncopated. The rhythms in “Lost Your Head Blues,” however, do not coincide with the beat. Many notes fall just before the beat, such as the “-by” of “baby.” “Didn’t” is stressed because it is longer, sustained between the second and third beats. Syncopation is a prized rhythmic component of ragtime and jazz, as heard in “I Got Rhythm” (Listening Example 1), Rhapsody in Blue (Listening Example 6). and “In the Mood” (Listening Example 9).
Rhythm is syncopated when accented or emphasized notes fall on weak beats, or in between beats. The rhythms in “Happy Birthday” are regular and coincide with the beat, so it is not considered syncopated. The rhythms in “Lost Your Head Blues,” however, do not coincide with the beat. Many notes fall just before the beat, such as the “-by” of “baby.” “Didn’t” is stressed because it is longer, sustained between the second and third beats. Syncopation is a prized rhythmic component of ragtime and jazz, as heard in “I Got Rhythm” (Listening Example 1), Rhapsody in Blue (Listening Example 6). and “In the Mood” (Listening Example 9).
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Polyrhythm
Polyrhythm, also called cross-rhythm, occurs when two conflicting rhythmic patterns are present simultaneously. The most common, as shown in Figure 5, are two against three (the upper example) and three against four (the lower example). Note that the meter does not change. In the first movement of "Liturgie de cristal" Quartet for the End of Time (Listening Example 14), the four instruments play polyrhythmic patterns.
Polyrhythm, also called cross-rhythm, occurs when two conflicting rhythmic patterns are present simultaneously. The most common, as shown in Figure 5, are two against three (the upper example) and three against four (the lower example). Note that the meter does not change. In the first movement of "Liturgie de cristal" Quartet for the End of Time (Listening Example 14), the four instruments play polyrhythmic patterns.
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Harmony and Common-Practice Tonality
Harmony occurs whenever two or more tones are sounding simultaneously. In Western cultures, pitch and harmony are typically organized using common-practice tonality (also called common-practice harmony). This system was developed in Europe beginning in the Middle Ages around 1750. Since then, layers of complexity have been added, vigorous challenges have been made by various composers, and knowledge of non-Western music traditions has increased dramatically. Despite these changes, conventions of common-practice tonality govern nearly all of the music produced or consumed in the Western world.
Harmony occurs whenever two or more tones are sounding simultaneously. In Western cultures, pitch and harmony are typically organized using common-practice tonality (also called common-practice harmony). This system was developed in Europe beginning in the Middle Ages around 1750. Since then, layers of complexity have been added, vigorous challenges have been made by various composers, and knowledge of non-Western music traditions has increased dramatically. Despite these changes, conventions of common-practice tonality govern nearly all of the music produced or consumed in the Western world.
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Chord and Key
A chord is three or more pitches sounding simultaneously. A book, or a forearm, pressed down on a piano keyboard will create a chord. However, the most common and useful chords do not employ immediately adjacent pitches. In music theory, the key is the world of pitch relationships within which a piece or substantial section of music takes place. “Key” in music theory is not to be confused with the piano key that you press to produce a single pitch. In terms of harmony, the “key” of a piece of music is the set of seven notes, or scale, that has been selected for use in that piece.
A chord is three or more pitches sounding simultaneously. A book, or a forearm, pressed down on a piano keyboard will create a chord. However, the most common and useful chords do not employ immediately adjacent pitches. In music theory, the key is the world of pitch relationships within which a piece or substantial section of music takes place. “Key” in music theory is not to be confused with the piano key that you press to produce a single pitch. In terms of harmony, the “key” of a piece of music is the set of seven notes, or scale, that has been selected for use in that piece.
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Key Signature
The key signature is a set of sharps or flats at the beginning of every staff that indicates the key of the music. The key signature signals which seven pitches make up the scale for that piece by indicating which pitches will be consistently raised or lowered. When an F# appears in the key signature at the beginning of the piece, that means all F’s in the entire composition are automatically raised, unless otherwise indicated (which would be done with a natural sign in front of the individual note). The key signature is a convenience. See the E major scale in Figure 6, shown on the keyboard and in two versions on the staff. The first notated version uses an accidental in front of each affected pitch. The second notated version begins with a key signature of four sharps (F#, C#, G#, and D#), indicating that the performer needs to sharpen any F, C, G, or D pitches he or she encounters.
The key signature is a set of sharps or flats at the beginning of every staff that indicates the key of the music. The key signature signals which seven pitches make up the scale for that piece by indicating which pitches will be consistently raised or lowered. When an F# appears in the key signature at the beginning of the piece, that means all F’s in the entire composition are automatically raised, unless otherwise indicated (which would be done with a natural sign in front of the individual note). The key signature is a convenience. See the E major scale in Figure 6, shown on the keyboard and in two versions on the staff. The first notated version uses an accidental in front of each affected pitch. The second notated version begins with a key signature of four sharps (F#, C#, G#, and D#), indicating that the performer needs to sharpen any F, C, G, or D pitches he or she encounters.
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Harmonic Progression
A harmonic progression is a series of chords or intervals that moves from tension (dissonance) toward resolution (consonance). Dissonance is the quality of a pitch, interval, or chord that makes it seem “unstable” or tense. The more dissonant a sound, the more the listener longs to hear a “resolution.” The opposite of dissonance is consonance, the quality of a pitch, interval, or chord that makes it seem a suitable point of rest or resolution. “Liturgie de cristal” (Listening Example 14) Quartet for The End Time employs considerable amounts of dissonance. Dissonance is relative. Some chords can sound dissonant or consonant depending upon what precedes them.
Ears accustomed to Western music expect dissonance to resolve. Tension is created as the listener waits for a tense interval or chord to come to resolution in something more restful. Dissonance and its resolution are central to harmonic progression. An example of this is the tritone. Play an F and B together on the piano (the “T” notes in Figure 7). The two most natural sounding resolutions are either G♭ and B♭, or E and C, as shown by the “O” notes on the keyboard diagrams in Figure 7.
Try playing the tritone followed by its resolution a few times. Then try playing it backwards (the “O” notes before the “T” notes) to see if there is a way to make the tritone sound more restful than the other interval. It is difficult, if not impossible. Any chord that contains a tritone will sound more dissonant than a chord without one.
A harmonic progression is a series of chords or intervals that moves from tension (dissonance) toward resolution (consonance). Dissonance is the quality of a pitch, interval, or chord that makes it seem “unstable” or tense. The more dissonant a sound, the more the listener longs to hear a “resolution.” The opposite of dissonance is consonance, the quality of a pitch, interval, or chord that makes it seem a suitable point of rest or resolution. “Liturgie de cristal” (Listening Example 14) Quartet for The End Time employs considerable amounts of dissonance. Dissonance is relative. Some chords can sound dissonant or consonant depending upon what precedes them.
Ears accustomed to Western music expect dissonance to resolve. Tension is created as the listener waits for a tense interval or chord to come to resolution in something more restful. Dissonance and its resolution are central to harmonic progression. An example of this is the tritone. Play an F and B together on the piano (the “T” notes in Figure 7). The two most natural sounding resolutions are either G♭ and B♭, or E and C, as shown by the “O” notes on the keyboard diagrams in Figure 7.
Try playing the tritone followed by its resolution a few times. Then try playing it backwards (the “O” notes before the “T” notes) to see if there is a way to make the tritone sound more restful than the other interval. It is difficult, if not impossible. Any chord that contains a tritone will sound more dissonant than a chord without one.
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