RHYTHM 02: The Essence of Rhythm
In the most general terms, rhythm just refers to the placement of musical events in time.
Our brains and experience dwell eternally in the present moment. Contained in this present moment is a well-calibrated sense of what has happened in the “recent” past- and a sensation of “flow”. That flow could be described as us moving through time from past to present to future. But in reality, experiences are flowing from our expectations, into our direct present experiences, then into memory.
We have learned to feel not only a regular pulse, but to hear multiple pulses and structures at different rates– then… the mojo (magic) happens. We some how experience this as a groove that gives is a different satisfaction than we would get hearing raindrops at random on a roof.
The biggest organizational feature is that we have pulses or beats. We enjoy music of many different rates of beats (tempos). We generally enjoy when the beats have a steady rate, neither slowing down or speeding up. But we also have notated and customary ways to speed up and slow down to add excitement or drama.
Those beats are grouped into cycles of 2 or 3 or 4 or 5 or 6 or 7, etc. beats. We call them measures, as that’s an almost customary way of approaching rhythm. Some cultures group beats in more elaborate, ornate or complex ways.
Next, we have a division of beats into smaller/faster units. It’s almost a fractal kind of thing. Slow measures made up of beats; beats made up of faster sub-divisions.
We can have secondary ways of grouping the beats and subdivisions to create more intricate patterns. For example, we can be in 4 beat cycles, but make melodic patterns of 3 beats super-imposed over that bigger structure. Or we can take beats divided into 3 and group them into 4’s to create a longer more interesting pattern. And we can have secondary ways of dividing beats, using tuplets of various kinds. You can divide beats into 2, 3, 4, 5, 6, 7, 8, etc. Or you can divide 2 beats into 3, 4, 5, 6, 7, 8, etc. And so on, any number of beats divided into any number of subdivisions, expressed as a ratio; e.g., 5 notes over 1.5 beats, etc., etc.
We can create these super-imposed “grids” of time, and place events of varying lengths on that grid. Using accents and ghost notes, we can add another dimension to a single line on a simple grid.
Those are most of the structural elements that make up rhythm in the real world.