Musical Rhythm: A Glossary of Terms

accelerando

Standard musical term used to indicate a speeding up or increase in tempo. Musical accelerandos commonly evoke a psychological feeling of excitement or arousal. See also rallentando.

accent

An event that is marked for consciousness (Cooper & Meyer, 1960; p.8). A sound that is made more salient or noticeable because of some physical property (e.g., increased loudness), or because the sound is unexpected (surprise), or because of the listener's increased attentiveness (e.g., meter). See also agogic accent, dynamic accent, phenomenal accent, structural accent, metrical accent.

age effects

The preferred tempo is known to change with age. Children prefer fast tempos and elderly prefer slower tempos. (Drake, Jones & Barucha, 2000).

agogic

Pertaining to duration.

agogic accent

The tendency for longer duration sounds to appear more salient or energetic than shorter sounds. See also accent, dynamic accent, metrical accent.

agogic syncopation

Syncopation that arises when metrically unstressed notes are longer in duration than metrically stressed notes. Compare onset syncopation. See also syncopation; dynamic syncopation; harmonic syncopation; tonal syncopation; meter.

Aksak meter

Any of a class of irregular meters commonly found in Bulgarian dances. For example, a repeated rhythmic cycle of 3+2+2.

auditory kappa effect

A perceptual interaction between pitch and time discovered by Bruno Repp. When three successive tones are separated by unequal pitch distances but equal temporal intervals, the temporal interval between the two closer pitches will appear to be shorter than that between the two tones farther apart in pitch (Repp, 1998: 134). The term "kappa effect" is borrowed from non-auditory research (Shigeno, 1986; Crowder & Neath, 1995).

augmentation

The musical procedure where a rhythm is made proportionally longer by increasing the notated duration of all notes in the rhythm. For example, an eighth-eight-quarter pattern may be augmented to quarter-quarter-half. The most common form of augmentation involves doubling the notated durations, however, augmentation may involve more complicated proportions. Contrasts with diminution.

backbeat

The tendency in a recurring four-beat sequence to emphasize the second and fourth beats rather than the first and third beats. The most characteristic feature of rock and roll, typically played on a snare drum.

beat

A recurring moment when tone onsets are more expected. In contrast to tactus, beats are differentiated from strong to weak and occur within a repeating pattern of beats, called a meter.

beat extraction

The use of computer programs to recognize and synchronize with the beat of some sound recording. A number of beat extraction algorithms have been developed, including those devised by Edward Large, Henkjan Honing, Peter Desain, and others.

binary meter bias

The tendency for (Western-enculturated) listeners to assume that beats and subbeats will form strong-weak (or weak-strong) pairs. Listeners tend not to expect triple meters or compound meters. See Brochard et al. 2003.

canonical timing

The timing implied by a strict or literal interpretation of a musical score. For example, where all quarter notes are precisely the same duration, all eighth notes are precisely half this duration, etc. See also expressive timing, deadpan performance.

click

When the duration of a sound is less than a time threshold (about 20 milliseconds) required for pitch recognition, the sound is heard as a click rather than a tone.

closure

The subjective sense of ending or completion -- as when experiencing the end of a sentence. In music, ending gestures are called cadences. Narmour has defined closure as the absence of psychological expectations.

compound meter

Any meter in which the beats are subdivided into three. E.g. 1-2-3-4-5-6 (compound duple), 1-2-3-4-5-6-7-8-9 (compound triple). Compare simple meter. See also binary meter bias.

conductor

Non-playing musician whose principle role is to synchronize and coordinate the rhythmic activities of multiple players. See also expressive timing, Director Musices.

contingent frequency

The likelihood of some event given the occurrence of some other event. For example, the likelihood of a downbeat given an event on the preceding upbeat.

deadpan performance

1. Performing a musical score literally, with no rubato. (See canonical timing.)

2. Performing a musical score in order to convey a neutral or dispassionate state. (See expressive timing.

diminution

The musical procedure where a rhythm is made proportionally shorter by decreasing the notated duration of all notes in the rhythm. For example, an eighth-eight-quarter pattern may be diminished to sixteenth-sixteethn-eight. The most common form of diminution involves halving the notated durations, however, augmentation may involve more complicated proportions. Contrasts with augmentation.

Director Musices

Computer program constructed by Johan Sundberg, Anders Friberg and Lars Frydén that uses a rule-based system for expressive interpretation of a musical score.

downbeat

The first beat in a measure. The moment in a metric schema that is most likely to coincide with an event onset. See also meter.

duple meter

Any meter that exhibits two main beats per measure. Duple meters may be either "simple" (beats are subdivided into 2), or compound (beats are subdivided into 3). See also triple meter; meter.

duration contrast

A principle of expressive performance proposed by Lars Frydén and Johan Sundberg where short notes are played shorter and long notes are played longer than the nominal score values.

dynamic accent

The tendency for louder sounds to appear more salient or noticed than quieter sounds. See also accent, agogic accent, metrical accent.

dynamic expectation

An expectation that arises "on the fly." These expectations are shaped by immediate experience, as when exposure to a novel work causes a listener to expect similar passages as the work continues. Dynamic expectations are liked to short-term memory. See also schematic expectation; veridical expectation.

echoic memory

A brief sensory memory that retains a "raw" or uninterpreted sound impression for roughly a second.

elision

Overlapping -- as when the last note of one musical phrase is also the first note of the ensuing phrase. See grouping.

entrainment

A synchronization of some aspect of our biological activity with regularly recurring events in the environment. (London, 2004, p.4)

expressive timing

Term coined by Bruno Repp (1986) to refer to the systematic timing features found in real musical performances that (1) deviate from a literal or canonical interpretation of a musical score, and that (2) evoke a sense of emotion, passion, or expressiveness. See also deadpan performance, canonical timing.

first-order

The probability of an event occurring given the prior occurrence of a single other event. Compare zeroth-order.

hemiola

A syncopation-like effect created when a musical passage changes meter for one or two measures. See also syncopation.

hypermeter

A recurring pattern of beats whose period of repetition is longer than a single bar or measure. In Western music, hypermeter commonly involves two- or four-measure patterns. The term was first used by Edward Cone (1968). See meter; downbeat.

implication-realization theory

A theory of musical expectation developed by Eugene Narmour. The theory distinguishes circumstances where listeners form strong expectations (implicative contexts) from circumstances where listeners form weak expectations. For implicative contexts, the theory proposes a number of Gestalt-like principles that shape the listener's expectations.

indifference interval

In early psychological research, the duration of a sound that is judged by listeners as being neither too long nor too short. Wilhelm Wundt reported an average indifference interval of 600 milliseconds. (Wundt, 1911).

irregular meter

As used by Western musicians, any meter that does not employ a recurring cycle of 2, 3, or 4 beats, or where beats are not subdivided in the same way. See Aksak meter.

isochronous

Equivalent in duration.

ITPRA theory

A theory of expectation developed by David Huron. The name "ITPRA" is a mnemonic for the sequence of five expectation-related responses: Imagination response; Tension response; Prediction response; Reaction response; Appraisal response.

JND

Just noticeable difference. Also known as the perceptual limen. The minimum amount of change in some physical parameter that is detected by a listener.

kappa effect

See auditory kappa effect.

lower-order

The probability of an event occurring in light of little knowledge of other prior events. Examples of lower-order probabilities include zeroth-order and first-order relationships. Contrasts with higher-order.

measure

(British = bar). A musical unit of time based on a recurring cycle of beats. The length of a measure is determined by the meter signature. In musical notation, measures are delineated by a solid vertical line or barline. See also meter, meter signature.

mental representation

The way that brains code the external world.

meter

1. A recurring pattern of beats that, in Western music, coincides with the duration of a bar or measure. 2. A beat schema that typically involves a cycle of between 2 and 5 beats with a distinctive way of subdividing beats. See compound meter; simple meter; duple meter; triple meter; irregular meter; Aksak meter; hypermeter; binary meter bias; beat; downbeat.

metrical accent

1. The increased salience The psychological tendency for a given meter, once established, to be maintained by a listener.

metrical inertia

The psychological tendency for a given meter, once established, to be maintained by a listener.

millisecond

Unit of time equivalent to one thousandth of a second.

motion induction

The tendency for some music to provoke listener movement, such as tapping feet, swaying, or even dancing.

motion metaphor

The tendency to describe musical experience through metaphors related to motion, such as speeding up, slowing down, arch gesture, rising, falling, etc.

onset syncopation

Syncopation that arises when note onsets coincide with metriclaly weaker (rather than metrically stronger) moments. Compare agogic syncopation. See also syncopation; dynamic syncopation; harmonic syncopation; tonal syncopation; meter.

paradoxical expectation

An event that is simultaneously expected and not expected. A phenomenon that can be traced to diverging schematic, veridical, or dynamic expectations. See also Wittgenstein's puzzle.

perceptual present

The temporal period during which the relationship between successive or concurrent events is salient. Paul Fraisse defines the perceptual present as "the temporal extent of stimulations that can be perceived at a given time, without the intervention of rehearsal during or after the stimulation" (Fraisse, 1978, p.205). See also psychological present. Compare echoic memory.

period

A musical unit, typically consisting of two phrases that form an antecdent-consequent pair. Common in Western music from the classical era.

phenomenal accent

Any form of accent arising from properties of the physical sound -- such as loudness (dynamic accent), duration (agogic accent), or pitch (tonal accent). See also structural accent, metrical accent.

premonition

A long-range feeling of anticipation.

psychological present

The subjective sense of "moment" or conscious "now." The duration of the psychological present has been variously characterized, with 5-6 seconds being a common estimate. See also perceptual present.

qualia

The distinctive subjective or phenomenological "feel" of some experience.

rallentando

Standard musical term used to indicate a slowing down or decrease in tempo. Musical rallentandos commonly evoke a psychological feeling of sluggishness or loss of energy. See also accelerando.

rhythmic attending

The theory, proposed by Mari Riess Jones and inspired by Daniel Kahneman (1973), that attention waxes and wanes according to periodic pulses ("attentional pulses"). Listeners are more attentive at particular moments in time.

ritard

The slowing down of a musical passage, commonly done at the ends of musical phrases. Especially marked at the ends of musical works.

rubato

The intentional speeding-up and slowing-down when performing music. See also expressive timing.

schema

A mental preconception of the habitual course of events.

schematic expectation

Expectations that arise from general knowledge of how events typically unfold -- such as familiarity with the "language" of jazz. Expectations linked to long-term memory. Compare dynamic expectation; veridical expectation.

second

International unit of for measuring time. See also millisecond.

simple meter

Any meter in which the beats are subdivided into two. E.g. 1-2-3-4 (simple duple), 1-2-3-4-5-6 (simple triple). Compare compound meter. See also binary meter bias.

statistical learning

Learning based on how frequently a particular event occurs, or how tightly two events are correlated.

stop-and-go

A musical device in which the music stops complete for a moment, and then resumes.

strong beat

A recurring moment when tone onsets are especially expected. See beat; downbeat; meter.

subito

Italian word meaning "sudden," as in subito piano (suddenly quiet).

subjective probability

The perceived or apparent likelihood (rather than the actual likelihood).

surprise

A common response to unexpected stimuli. A characteristic facial expression may be evoked where the mouth remains open (facilitating breathing) and the eyelids remain retracted (facilitating perception).

syncopation

A distinctive rhythmic effect produced by a class of violations of temporal expectation. Specifically, where an event coinciding with a relatively weak metrical moment fails to be followed by an event on an ensuing stronger metrical moment. See also agogic syncopation, dynamic syncopation, harmonic syncopation, onset syncopation and tonal syncopation.

tactus

A basic pulse that typically falls in the range between 0.6 and 0.75 seconds (80 to 100 events per minute). The rate at which a listener will spontaneously tap while listening to music. The tactus commonly coincides with the beat rate. However, where beats are perceived as stronger or weaker events within a recurring meter, the tactus remains an undifferentiated pulse.

tempo

The speed of music, typically expressed in beats per minute.

tempo drift bias

The subjective tendency for most listeners to hear a true steady beat as either getting faster or slower. Sofia Dahl (2005) has shown the individuals appear to have a constant postive or negative tempo bias when hearing a physically steady beat.

temps courts

In the theory proposed by Paul Fraisse, a distinction is made between long and short contrasting durations. Short durations (temps courts) evoke little sense of duration, and are typically sounds shorter than about 400 milliseconds (Fraisse, 1978). Sequences of short sounds can evoke a sense of collection but tend not to evoke the passage of time during individual events. See temps longs. See also categorical perception.

temps longs

In the theory proposed by Paul Fraisse, a distinction is made between long and short contrasting durations. Long durations (temps longs) evoke a true sense of duration or passing time, and are typically sounds longer than about 400 milliseconds (Fraisse, 1978). See temps courts. See also categorical perception.

tendency moment

Moment with a meter that evokes a strong expectation of an event onset coinciding with some ensuing metrical moment. An example of a tendency moment is the pickup, upbeat, or anacrusis. See also meter.

Thomassen's accent

A computational model of pitch-related tonal accent based on experiments carried out by Joseph Thomassen (1982). Tones are perceived as more accented when they coincide with a change of pitch direction or contour. Thomassen's accent is greatest for tones that are approached from below and then descend. Slightly less accented are tones that are approached from above and then ascend. Thomassen's accent is known to be more consistent with musical practice than other popular notions of tonal accent (Huron & Royal, 1996). See also phenomenal accent.

tonal accent

A weak type of phenomenal accent that can be traced to the manipulation of pitch. Historically, six conceptions of tonal accent have been proposed: (1) the higher the pitch the more accented, (2) the lower the pitch the more accented, (3) the larger the interval the more accented, (4) ascending large intervals, (5) descending large intervals, (6) changes of pitch contour. The conception of tonal accent known to be most consistent with musical practice is a model proposed by Joseph Thomassen. See Thomassen's accent. See also agogic accent, dynamic accent, phenomenal accent.

tonal syncopation

Syncopation that arises when pitch patterns fail to coincide with the prevailing meter. See also agogic syncopation; dynamic syncopation; harmonic syncopation; onset syncopation; meter.

triple meter

Any meter that exhibts three main beats per measure. Triple meters may be either "simple" (beats are subdivided into 2), or compound (beats are subdivided into 3). See also duple meter; meter.

useful tempos

The range of tactus periods that are considered musically useful. Peter Westergaard offers the following characterizations:

Tempo (beats per minute)	Inter-onset Interval (in seconds)	Subjective qualia
30	2.00	too slow to be useful
42	1.41	very slow
60	1.00	moderately slow
80	0.70	moderate
120	0.50	moderately fast
168	0.35	very fast
240	0.25	too fast to be useful

(after London, 2004; p.28)

veridical expectation

Expectations that arise from past knowledge of a familiar sequence of events -- such as familiarity with a particular musical work. Expectations linked to episodic memory. See also dynamic expectation; schematic expectation.

vestibular theory

A theory proposed by Neil Todd that suggests that the perception of rhythm arises from simulation of the vestibular system. The theory notes that the cochlea is both the organ of hearing and the organ of equilibrium (sense of orientation in space). The theory proposes that low frequency components of low amplitude cause activation of the fluid in the semicircular canals of the cochlea and give rise to a weak sensation of movement.

Wittgenstein's puzzle

The paradox, posed by the Austrian philosopher Ludwig Wittgenstein, of how it is possible to be surprised by musical events that one knows will happen. How, for example, can a "deceptive cadence" continue to sound deceptive, even when a listener is familiar with the music? See also paradoxical expectation.

zeroth-order

The raw probability of an event occurring without any consideration of the possible influence of surrounding or neighboring events. Compare first-order.