1.7: Rhythm
When you think of the word rhythm, the first thing that might pop into your head is a drum beat. But rhythm goes much deeper than that. Earlier, we defined music as intentional organization of sounds. Rhythm is the way the music is organized in respect to time. It works in tandem with melody and harmony to create a feeling of order. The most fundamental aspect of rhythm is the beat , which is the basic unit of time in music. It is the consistent pulse of the music, just like your heartbeat creates a steady, underlying pulse within your body. The beat is what you tap your feet to when you listen to music. Imagine the beat as a series of equidistant dots passing through time as in the Figure \(\PageIndex{1}\).
It should be noted that the beat does not measure exact time like the second hand on a clock. It is instead a fluid unit that changes depending on the music being played. The speed at which the beat is played is called the tempo . At quick tempos, the beats pass by quickly, as represented by Figure \(\PageIndex{2}\) below showing our beats pressed against each other in time.
At slow tempos, the beats pass by slowly, as seen inFigure \(\PageIndex{3}\) showing our beats with plenty of space between them. Composers often indicate tempo markings by writing musical terms such as “allegro” which indicates that the piece should be played at a quick, or brisk, tempo.
In other cases, composers will write the tempo markings in beats per minute (BPM), when they want more precise tempos. Either way, the tempo is one of the major factors in establishing the character of a piece. Slow tempos are used in everything from sweeping love songs to the dirges associated with sadness or death. Take for example, Chopin’s famous funeral march:
Fast tempos can help to evoke anything from bouncy happiness to frenzied madness. One memorable example of a fast tempo occurs in “Flight of the Bumblebee,” an orchestral interlude written by Nikolai Rimsky-Korsakov for his opera The Tale of Tsar Saltan, which evokes the busy buzzing of a bee.
Beats are the underlying pulse behind music, while meter refers to the way in which those beats are grouped together in a piece. Each individual grouping is called a measure or a bar (referring to the bar lines that divide measures in written music notation). Most music is written in either duple meter (groupings of two), triple meter (groupings of three), or quadruple meter (groupings of four). These meters are conveyed by stressing or “accenting” the first beat of each grouping. In the figure below, you can see examples of triple and quadruple meter. The first beat of each bar is larger than the rest to indicate this accent. These larger beats are often referred to as strong beats, while the smaller beats between them. are referred to as weak beats.
To illustrate how vital rhythm is to a piece of music, let’s investigate the simple melody “Mary Had a Little Lamb.” Below, the melody and chords are conveyed through standard musical notation. The meter is indicated by the two numbers four over four. (This is known to music readers as the time signature .) This particular time signature is also known as “common time” due to the fact that it is so widely used. The top number indicates the meter, or how many beats there are per measure. The bottom number indicates which type of note in modern musical notation will represent that beat (in this case, it is the quarter note). The vertical lines are there to indicate each individual measure. As you can see, the melody on the top staff and the chords on the bottom staff line up correctly in time due to the fact that they are grouped into measures together. In this way, rhythm is the element that binds music together in time.
One way to add a sense of rhythmic variation to music is through the use of syncopation. Syncopation refers to the act of shifting of the normal accent, usually by stressing the normally unaccented weak beats or placing the accent between the beats themselves as illustrated in Figure \(\PageIndex{6}\) .
Syncopation is one of the defining features of ragtime and jazz, and is one aspect of rhythmic bounce associated with those genres of music. In Figure \(\PageIndex{7}\) below, it is the circled notes on the weak beats which are accented or emphasized.
In some cases, certain types of music may feature the use of a polyrhythm , which simply refers to two or more different rhythms being played at the same time. A common polyrhythm might pit a feeling of four against a feeling of three. Polyrhythms are often associated with the music of Africa. However, they can be found in American and European music of the twentieth century, such as jazz. Listen to the example below of Duke Ellington playing his signature song, the Billy Strayhorn composition “Take the A Train.” You will notice that the beats in the piece are grouped as four beats per measure (Figure \(\PageIndex{8}\)). Pay special attention to what happens at 1:32 in the video. The horns begin to imply groupings of three beats (or triple meter) on top of the existing four beat groupings (or quadruple meter). These concurrent groupings create a sense of rhythmic tension that leads the band into the next section of the piece at 1:38 in the video.
Ex. 1.16: Duke Ellington “Take the A Train”