A.Diederich – International University Bremen – USC – MMM – Spring 2005

Rhythm and timing

Clarke, E.F. Rhythm and timing in music. In Deutsch, D. Chapter 13 Krumhansl, C.L. (2000). Rhythm and pitch in music cognition. Psychological Bulletin, 126, 1, 159 – 179 Davies, J.B. (1978) The psychology of music. Stanford University Press.

A.Diederich – International University Bremen – USC – MMM – Spring 2005

Two types of time relations are fundamental to the temporal organization, or rhythm, of musical sequences: the segmentation of an ongoing sequence into

temporal groups of events based on their durational values

the extraction of an underlying temporal regularity or beat

A.Diederich – International University Bremen – USC – MMM – Spring 2005

Basic psychological research on rhythm

Stimulus Patterns constructed of tones of varying

durations or very brief tones at varying delays Pitch of the tones is not simultaneously varied

A.Diederich – International University Bremen – USC – MMM – Spring 2005

Response Time measurement of most interest is the time

between the onset of successive events (inter-onset interval IOI)

Time is measured in milliseconds (ms) rather than in beats per minute (bpm) 60 bpm = 1000 ms 120 bpm = 500 ms 240 bpm = 250 ms

Range of focus: 100 ms to 5000 ms

A.Diederich – International University Bremen – USC – MMM – Spring 2005

Task of participant (P)1. Verbal estimation: E presents temporal

interval, P gives verbal estimate of its duration (in clock time)

2. Production: E states the duration (in clock time), P produces the interval

3. Reproduction: E presents a temporal interval, P reproduces it

4. Method of comparison: E presents two temporal intervals in succession, P judges the relative duration

A.Diederich – International University Bremen – USC – MMM – Spring 2005

Time perception

If the time between events ( e.g., brief tones) is too short (< 100 ms), listeners hear the sequence as a single, continuous event.

If intervals are much greater than 1500 ms, listeners have difficulty grouping the sounds, which seem disconnected from one another.

Larger, hierarchically organized rhythmic patterns consisting of groups can be formed out to approximately 5 s.

A.Diederich – International University Bremen – USC – MMM – Spring 2005

Perceived duration: Very short intervals tend to be overestimated. Large intervals tend to be underestimated. In the range of 40 to 600 ms, the subjective

duration of time interval is proportional to the physical duration plus a constant of approximately 80 ms

Filled duration illusion: A duration filled with stimulus events is perceived

as being longer than an identical duration empty of any external events.

A.Diederich – International University Bremen – USC – MMM – Spring 2005

Grouping

When listeners hear a sequence of identical sounds, they tend to group them by twos, fours, or less often by threes (subjective rhythmization).

The number of elements in groups depend on tempo; groups with more elements are formed at faster tempo.

A.Diederich – International University Bremen – USC – MMM – Spring 2005

Objective rhythmization

Different sounds (longer, louder, different pitch, followed by longer pause)

Pauses – strongly mark group endings Group of three or four: 600 to 700 ms pauses Pauses longer than 1800 ms are not produced.

Lengthening a sound has similar effect.

A.Diederich – International University Bremen – USC – MMM – Spring 2005

Element duration and intensity trade off with each other. A sound that is lengthened is perceived as more intense. A more intense sound is perceived as longer.

Longer and more intense sounds are heard as accented, and these elements tend to define the beginning of a group.

Higher pitched sound tends to define the beginning of a group.

A.Diederich – International University Bremen – USC – MMM – Spring 2005

The work of Paul Fraisse to an understanding of rhythm in music are the following:

1. The perceptual present as the dividing line between the direct perception of duration and its estimation.

2. The fundamental status of pendular motion and the close association between rhythm and movement.

3. The distinction between rhytmia and arhythmia, based on the distinction between a continuous and a bimodal distribution of duration ratios between successive intervals.

A.Diederich – International University Bremen – USC – MMM – Spring 2005

4. The existence of categorical distinction between two types of duration (temps long and temps court) in rhythm, in a mean duration ratio of 1:1 or 2:1, and with the quality of duration and collection, respectively.

5. A threshold between these categories at a value around 400 – 600 ms.

6. (The operation of two complementary principles (assimilation and distinction) that preserve both the integrity and distinctiveness of the two categories. Based on the theory of Piaget)

A.Diederich – International University Bremen – USC – MMM – Spring 2005

Implications of basic research for rhythmic patterns in music

1. Although humans quite accurately estimate time and detect small differences in duration, the most impressive abilities are found in the perception and production of rhythms. (The patterns of duration, rather than absolute durations, are psychological primary.)

2. Rhythm perception is strongly linked to rhythm production.