Pulseless onset timing
To decide how to specify onset timing in your score, the first question to ask is whether the music has a regular “pulse” or not. If you can tap your foot to the music, it probably has a pulse, even if you are tapping very slowly or at a fluctuating rate.
If you can’t detect a pulse in the music, you can still specify onset timing by using a linear scale of time as measured by the clock, in minutes and seconds. A given unit of length along the horizontal axis should be assigned to a given unit of time, for instance 1cm = 1 second. The time scale to use will depend on the density of information to be included in the notation: for instance, the maximum number of onsets per second. The time scale can be indicated with a bracket above the beginning of the score.
Symbols for sounds of either specified or unspecified duration can then be spaced along the layer line(s) according to their onset timing. The left-hand edge of each symbol represents the onset of the sound, while for sounds of specified duration, the right-hand edge represents the end or “release” of the sound.
For our first actual score, we will use an example of a single drum playing a series of strokes of indefinite pitch without a discernible pulse.
Since the drum sounds are impulsive and die away rapidly without the player’s control, their duration is left unspecified by representing them with “wedge” symbols. Since they have no definite pitch, and only one kind of sound is used, all the wedges are placed directly above the layer line. Onset timing is specified by the horizontal spacing of the wedges, showing a gradual but uneven acceleration. As the strokes come closer together, the wedges start to overlap, but their left-hand edges are still visible, specifying the timing of each onset. (For this score, the onset timing was determined with the aid of sound analysis software; see Measuring onset timing with a waveform graph.)
Most music, however, does have a pulse, and in that case we can specify onset timing in relation to the pulse rather than the clock.
Source of audio:
“Woodo-kut” from Samul-Nori: Drums and Voices of Korea (Seoul: Oasis Record Co., ORC-1041), track 2.