Specifying other information where duration is unspecified
We are now able to notate rhythms either singly or in simultaneous combinations, specifying the sound source(s), tempo, and onset timing while leaving both pitch and duration unspecified (see Onset timing with more than one layer). For a percussion instrument of indefinite pitch, or an ensemble of such instruments, this may be enough.
However, many percussion instruments of indefinite pitch use more than one kind of sound and playing technique. For instance, there may be deliberate contrasts between drum strokes played with a stick and with the bare hand, or by the strong and weak hands of the drummer, on the same instrument. It may be important for our score to capture such contrasts.
Remember that sounds of unspecified duration are represented by discrete symbols of fixed shape (as opposed to the extendable symbols used for sounds of specified duration). By default, the “discrete symbol” is a wedge placed directly above a layer line; but this is only one option. When duration is unspecified, other information can be given about the sounds, both by using different shapes and by placing them below as well as above the layer line.
In our drum kit notation, for instance, we used the spaces below and above the layer lines to notate the sounds made by different instruments in the drum kit (see Onset timing with more than one layer). We could do the same for other percussive patterns based on contrasting sounds, such as the famous “stomp-stomp-clap” riff in Queen’s “We Will Rock You.”
Alternatively, we could save space by placing all the symbols above the layer line and using different shapes for the different kinds of sound—for instance, a square for the stomp and a wedge for the clap. In this case, we would need to provide a “key” at the beginning of the score to indicate what each shape represents.
Either solution is acceptable so long as the meaning of the symbols is made clear to the reader. Global notation does not dictate how to notate a given type of sound, but always provides a range of options from which users can choose according to their needs. For instance, there is often a trade-off between saving space and minimizing the number of different symbols needed, and these choices can only be made in relation to the purposes of a particular score.
The choice of shapes, however, can usefully be guided by certain consistent principles. Remembering that the left-hand edge of the symbol specifies the moment of onset, this is most clearly done by using shapes with a straight and vertical left-hand edge: hence, squares or D-shapes are preferred to circles or stars. Unless contrasts of volume or accentuation are intended, the symbols should be roughly equal in visual prominence, which is achieved by making them roughly equal in surface area. This may mean that the linear height of a square, for instance, is less than that of a wedge; and since rows of symbols look best with their centers aligned vertically, this in turn may mean that symbols of square outline don’t touch the layer line, as in the above example.
In addition to using different shapes, information may be conveyed by a contrast between filled-in and open shapes, for instance to represent obligatory and optional strokes in a variable drumming pattern.
When using shapes other than the wedge, the time scale should be set (see Pulseless onset timing) such that the symbols don’t overlap, as this would otherwise obscure the onset timing.
As regards the positioning of symbols above and below a layer line, a good general practice is to be guided by approximate pitch range: deep and resonant drum strokes are usually better placed below the line to allow for contrasts with sounds of higher relative pitch such as rimshots. If the spaces above and below the line represent the right- and left-hand drums of a pair, users accustomed to keyboard instruments will find it more intuitive to place the left-hand strokes below the line and the right-hand strokes above, rather than the reverse.
Some of these principles might be illustrated by notating the repeating patterns in a West African drumming ensemble—in this case the genre Kpegisu from the Ewe people of Ghana.
The hand-held double bell can produce two sounds differing in approximate pitch, though not tuned to precise pitches; these are notated above and below the layer line. The lower-pitched bell is used only on the first beat of the cycle, and even then only optionally, hence the parentheses.
The rattle, a gourd wrapped in a net strung with beads, can be struck against the player’s thigh or the palm of their free hand. The “palm” and “thigh” strokes are distinguished by notating them above and below the layer line respectively.
The kidi drum uses two different kinds of stroke: a “bounce” in which the stick is allowed to bounce off the drum head, producing a resonant sound, and a “press” in which the stick is held against the drum head after striking, muting the sound and raising its approximate pitch. These, again, are distinguished by notating them on opposite sides of the layer line. In addition, strong- and weak-hand strokes are distinguished by using squares and wedges respectively.
The kagan drum uses only “bounce” strokes, so all of its sounds are notated below the layer line, like the bounce strokes of the kidi. However, some of these strokes need not be played in every repetition of the pattern, and these “optional” strokes are indicated with open rather than filled-in shapes.
These are just some examples of how differences in the form and position of symbols may convey further information where duration is unspecified. Users of global notation are free to make up their own “codes” for conveying such information, always provided the code is explained at the beginning of the score.
We have now covered the rudiments of how to specify onset timing, using only examples with unspecified pitch. But most music uses sounds of definite pitch, and for most purposes we will want to specify pitch in our scores. Now we are ready to start considering how to do that.
Next: Specified pitch
Kpegisu percussion score based on staff notation in:
Locke, David. 1992. Kpegisu: A War Drum of the Ewe. Featuring Godwin Agbeli. Temple, Arizona: White Cliffs Media Company. At p. 114.