Polyrhythms
Polyrhythmic literally means "many rhythms". A polyrhythm occurs when two or more rhythmic pulses are played simultaneously.
There are 2 basic ways to create a polyrhythm:
- Any even note grouping (½, ¼, 1/8, 1/12 or 1/32 notes) subdivided by an even number.
- Any odd note grouping (triplets, groups of 5,7,9,11 etc.) subdivided by an even number.
There are 3 ways to "subdivide":
- Sticking
- Sound Source
- Accent
or a combination of the these three.
The amount a particular note grouping is subdivided by, distinguishes different polyrhythms, e.g.:
These eighth notes have been subdivided by 3 through the use of accents. This is a 3 against 8 polyrhythm. All 3 against 8 polyrhythms take 3 bars to complete one cycle. (3 times through the 8 pulse or 8 times through the 3 pulse). This formula is the same for all polyrhythms.
The following fill-ins are all 3 against 16 polyrhythms over one bar. The subdivisions of 3 have been created by sticking and or sound source selection. Because these polyrhythms do not evenly resolve over one bar, it is necessary to change the subdivision pattern at the end of the bar. In this case the sticking pattern of the last two sixteenth notes has been changed:
becomes
Finishing a fill with the left hand facilitates an easier return to the beat.
Polyrhythms become more difficult as the duration held increases. Try these 2 bar 3 against 8 polyrhythms.
Here are the complete cycles of the 3 against 8 polyrhythms created with the sticking R L L and R R L. Fluency over polyrhythms relies upon the ability to distinguish both the polyrhythm and the pulse dictated by the time signature, simultaneously. In this case, the * time signature is accentuated by the quarter note bass drum pulse.
