Musical Terms and Definitions

Measure or Bar

Each group of beats is called a measure or bar. Thus, if a song is in a meter of four, each measure or bar has four beats. The first beat of each measure is called the downbeat. It is usually emphasized more strongly than the other beats.

Non-Metric Music

In certain types of music, both Western and non-Western, there is no discernible organization according to meter. Such music is called "non-metric" or is said to possess "free meter."

Polyrhythm

In complex music, where rhythms based on different subdivisions of the beat are heard simultaneously, "polyrhythms" are created. "Poly-" means "many" and thus polyrhythm literally means "many rhythms"). Such music may lack a discernible beat or pulse because of its complexity.

Polymeter

In some types of music or certain compositions, the meter may change within the course of a piece. This is often called "hemiola" when it is done repeatedly in an alternating fashion. A good example is "I like to be in A-me-ri-ca," from West Side Story by Leonard Bernstein, which switches from 2 beats to 3 beats---you can experience this by quickly saying the following and giving emphasis to the bold-face words: one two three four five six, one two three four five six.

Subdivisions

In the same way that measures are divided into beats, beats are themselves divided into smaller units or subdivisions. When a beat is divided into two smaller units (or a multiple of two), this is called a duple subdivision. When a beat is divided into three smaller units, this is a triple subdivision, and so on. The basic unit of a duple subdivision is called an "eighth-note." The basic unit for a triple subdivision is called a "triplet-eighth."

Syncopation

Most commonly, accents fall on the strong beat (or beats) of each measure (especially the downbeat). If an accent falls on a weak beat or in-between beats, this is called syncopation, or syncopated accent. Sometimes, syncopation will be a defining characteristic of a musical style. For example, one of the main distinctions between classical music and jazz is that in classical music, accents in a piece of music in a meter of 4 (the most common of all meters) tend to fall on the first and third beats of each measure. Thus, beats 2 and 4 are called the "weak beats." By contrast, in jazz, beats 2 and 4 of each measure are generally emphasized, giving the music a very different rhythmic feel. This is an important aspect of the "swing feel" characteristic of jazz and related forms.

Asymmetrical Meter

Most of the music with which Western listeners are familiar is in either duple or triple meter. However, some music is in other meters, like 5 or 7. Since these groupings can not be divided evenly into subgroups of two or three, they are called asymmetrical meters. Dave Brubeck's "Take Five," in a meter of 5, is a good example.

Beat

Music is often said to have a pulse. The unit of pulse is called a beat. When you tap your foot to music, you are usually tapping with the beat

Accent

Specific points in the music that are in some way emphasized are called accents. Most commonly, the accent is achieved by playing the accented note (s) louder than the other notes in the melody.

Tempo

Tempo is the speed or rate with which beats pass. When the beats proceed at a regular rate, the tempo is constant, as in the ticking of a clock. If the time between beats gets faster and slower, the tempo is said to be rubato. If the beats get progressively faster, the tempo is accelerating. If they get progressively slower, the tempo is decelerating.

Meter

The beats in music are rarely undifferentiated. They are usually heard as being grouped. Meter describes the type of grouping. Groupings of beats into units of two or four are found in duple meters (e.g., most rock and jazz tunes, polkas). Groupings of beats into three are found in triple meter (e.g., waltzes). Whether music has a single meter, changing meters, or no meter, all music has rhythm in the sense that all music involves the organization of sound in time.

Rhythm

The organization of sounds in time. In music, the organization of rhythm is built upon beat, tempo, meter, accent, and subdivision.