Rhythm is how we perceive and measure time. Humanity awoke to the awareness of passing of time in the passing of days and seasons. Logically, then, days and years became the basis of the language of time. Dividing days creates hours, minutes, seconds; then milli-, micro-, nano-, pico-, femto-, and attoseconds (one quintillionth of a second).
Steady repetitive rhythms like these are called periodic rhythms. Periodic rhythms are the building blocks of the universe—the way the universe works. Except for orbit, rotation, and revolution, the terms describing the structural rhythmic foundations of the universe also describe the foundations of music. They include cycle, beat, pulse, and frequency.
Sense of Rhythm
Your sense of rhythm is your ability to perceive and measure time. Everyone is born with an innate sense of rhythm, which begins with the sensation of the mother’s heart beating through the womb. The ability to musically feel and express rhythm is a talent like any other, and with practice, your sense of rhythm can improve.
A musician’s task is to play sounds in time, so it stands to reason that the deeper a musician understands what rhythm is, the better his or her sense of rhythm can be. One way to get a better understanding is to know the different kinds of rhythm a musician encounters:
Any steady repetitive action creates a pulse. Musical pulse, most usually provided by a drummer, tapping foot, metronome, or even a person’s inner pulse are indispensable for the performance of music.
The heartbeat is the best example of pulse. While not a very steady pulse by musical standards, it remains the best metaphor for the importance of pulse in music—pulse gives life to music.
The metronome is a musical instrument that provides an even pulse, and it’s an invaluable tool for working on one’s sense of rhythm. It’s not an accident that the traditional metronome provides a pulse more or less within the rhythmic parameters of the human heart.
Beat usually refers to the organized pulse that a drummer plays. Often, the repeating pattern of a beat identifies a style of music—there is a swing beat, a rock beat, and reggae beat.
Beat is also referred to as musical meter. The most simple meters—2/2 or 4/4—refer to a steady pulse subdivided into equal measures. In 4/4 meter, you play four quarter notes per bar (measure).
Another aspect of beat and meter is how loud each pulse is played. In 4/4 rock music, the drummer might accent the first and third pulses—the downbeats. Reggae, by contrast, accents pulses two and four.
Tempo is the speed at which a piece of music is played. On a piece of music there will sometimes be a metronome number in bpm to indicate tempo. Also, Italian words may give an indication of tempo, such as adagio (slow) or allegro (fast). (See page 22, “Words Into Music,” for some definitions.)
Frequency refers to the number of times one event occurs in a specific period of time.
Frequencies, like pulse, are the essence of music. In fact, the two terms are essentially the same thing. When frequency is measured in minutes, we are referring to beats per minute, or tempo. When frequency is measured in seconds, we are dealing with cycles per second, or pitch.
We can talk about pitch in an article on rhythm because pitch is simply a very fast pulse. We hear a pulse if a sound cycles at a frequency between about 30 and 300 times per minute. We hear a pitch if a sound cycles at between about 16 and 16,000 times per second. A pitch is a pulse so fast, we hear one continuous sound.
Looked at this way, musicians concerned primarily with beat and musicians concerned primarily with pitch are working toward the same goal—a greater awareness of pulse and how to express their sense of rhythm.
—Adapted from Rhythm: What It Is and How to Improve Your Sense of It by Andrew C. Lewis (Rhythmsource press, San Francisco, CA, 2005). Learn more at www.rhythmsource.com.