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Guidelines for composing
Rhythmic Processes
A range of different approaches to rhythmic organisation may be drawn upon to create rhythmic interest in the composition. It is a good idea to try to be more adventurous with your rhythmic ideas rather than rely on more conventional clichés such as 3/4, 4/4 or 6/8. Some devices to consider follow.
- Additive rhythms
These add differing metrical structures together to create a more unpredictable element to the rhythmic flow of a passage. This can occur as a regular pattern such as 2/4, 2/4, 3/4 (e.g. Stravinsky Three Pieces for String Quartet Movt. 1) or as an irregular pattern, as in the following example:
4/4/, 4/4/, 4/4, 5/4, 4/4, 4/4, 4/4, 3/4, 4/4 and so on.
In this sequence the 5/4 bar adds a pulse unpredictably while the 3/4 bar loses a pulse. This affects the regularity of the metre and creates rhythmic uncertainty. More complex additive rhythms can be used such as 4/4, 4/4, 3/8, 4/4, 7/8, 4/4, 3/4, 4/4 and so on, where the constantly changing metres creates great flexibility. This technique should be used carefully as it creates greater difficulty for the performers and for synchronising the ensemble.
- Divisive rhythms.
This technique subdivides the bar into a non-conventional grouping of the pulses to create differing patterns of accentuation. For example, consider the 4/4 metre instead as 8/8, or eight semiquavers and reconfigure the grouping as follows.
In his Fifth String Quartet, Bartok uses divisive rhythms in Movement 3 (Scherzo) which create a dance-like accentual pattern to generate rhythmic drive:
- Augmentation/diminution of a rhythmic cell.
A rhythmic cell is a small rhythmic grouping which may be manipulated in various ways. In Example 7 the rhythmic cell is augmented by doubling the rhythmic values and undergoes diminution by halving the rhythmic values.
In each case the identity of the rhythmic cell is maintained. Such a technique used carefully can provide rhythmic unity to a section or movement of a work.
- Symmetrical rhythms
These rhythmic formations are constructed so that they are symmetrical around a central point (axis of symmetry).
- Syncopation
This involves displacing the normal accentual pattern by placing an accent on a pulse other than the conventional strong beat of the bar.
Syncopation can be used to create a jazz influence or a “swung” feel, or to generate more rhythmic variety and interest as opposed to a ‘straight’ 4/4 or 3/4 feel.
- Rhythmic ostinato
This technique involves the creation of a rhythmic pattern stretching over 1, 2 or sometimes more bars which is then used as a repeated sequence to form an underlying layer in a passage.
The tango rhythm and its alternate form are examples of a single bar ostinato.
Task 8
Compose five contrasting rhythmic ideas selectively drawing upon the above techniques. Up to 2-3 bars should be sufficient. Notate them purely as rhythmic ideas- don’t worry too much about pitch for this. This is part of the pre-compositional process and will give you a short catalogue of rhythmic possibilities to draw upon when you come to begin writing your piece.
Rhythmic Gesture
You may prefer to approach these rhythmic formulas in a more expressive way. Using this method enables you to be more improvisational in the development of rhythmic material. With this technique the idea is to respond to a particular gesture or mood using rhythm as the vehicle to generate ideas. For example a response to the musical idea of ‘agitato’ (agitated) might involve shorter, more irregular attacks; a factory-like mechanical gesture might involve the repetition of a cell to convey the regularity of a production line, or a serene mood might have sustained lines layered with freer attack rhythms tied over the bar lines to de-emphasise pulse.
This approach enables the composer to directly link up with the compositional idea and to improvise with it using rhythmic processes. A wide range of gestures may be drawn upon often from listening to the world around us and capturing the rhythm such as birdsong, steps on the pavement, trains, people talking or dance. Usually only two or three are sufficient to work with, develop or transform so it’s important to be selective and relate them to the compositional idea. In general, try not to cram too many conflicting ideas into a short space of time- rather do more with fewer, select ideas.
Task 9
Consider what type of rhythmic gestures might relate to your underlying compositional idea.
Choose three which you think might effectively complement or contrast and notate your interpretation of their rhythmic structure. They may be a 1 or 2 bar cells or a 3-4 bar rhythmic idea.
The rhythms devised in tasks 9 and/or 10 can then be adapted to form the basis of:
- the motivic ideas
- chordal sequences as events in themselves or to accompany the motivic idea
- layers which can generate more complex rhythmic textures.
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