Percussion instruments, which produce a sound when they are struck, shaken, or scraped, fall into two broad categories: indefinite pitch and definite pitch. Timpani appears on the orchestral score above indefinite pitch instruments such as drums and cymbals. Below these are instruments of definite pitch such as orchestra bells, xylophone, and celesta. The indefinite pitch instruments are often notated on a single line rather than on a staff.
Most orchestras have at least three percussionists available, and several instruments may be notated in a single part if they are not played simultaneously. The number of players, instruments, tunings, and special directions must be indicated at the beginning of the score and parts. Many times the most effective percussion part consists of a small score for the entire section, excluding timpani, showing how all the instruments interact. This arrangement allows players to use their individual strengths and provides cues for entry.
The percussion section is used primarily in two ways: (1) for melodic or thematic purposes, where the pitched instruments such as timpani and mallets are most useful, and (2) to provide coloration and special effects, where unpitched instruments like the triangle, cymbals, or tambourine might be used. The dynamic range of the percussion section can be greater at both extremes than all the rest of the instruments in the orchestra combined, so include very careful directions regarding volume and intensity.
Logistics are a prime consideration when dealing with percussion. If several instruments playing at different times in the music can be handled by one performer, include literal directions in the part well in advance of each change. Be sure to allow the performer time to place cymbals on their stands or walk around the timpani. In short, anticipate every movement the percussionist must make when constructing the part. Large notation and clearly written directions are important because these players are not often stationary and must look away from the music frequently.
Single stroke: The basic gesture of striking an object once, setting up vibrations. Combinations of strokes, or ornamented notes, are particularly common in snare drum writing. Occurring slightly before the beat, these ornaments are used to broaden the sound. They are notated as follows:
FIGURE 5.1 Ornaments and rolls: (a) flam, (b) ruff, (e) four-stroke ruff, (d) roll, (e) roll with even division of the beat
Flam: A rapid combination of two single strokes, one played by each hand.
Three-stroke ruff: A rapid combination of three strokes, most often L-L-R or R-R-L; the term "drag" is also used.
Four-stroke ruff: Four rapid strokes, L-L-L-R, R-R-R-L, or alternating sticks.
Roll: Rapid alternating strokes; any time mallets are used, a single-stroke roll is executed.
Open roll (rudimental roll): Consists of strokes with a single rebound; used primarily by marching band snare drums.
Concert roll (closed, multi-bounce, or press roll): Consists of strokes with two or three rebounds, creating a sustained effect. This is normally the type of roll executed by orchestral snare drummers.
The trill symbol should not be used to specify a roll, because it indicates the alternation between two different pitches. Note values included in a roll are tied to avoid undesired accents. A roll between two instruments is notated as a tremolo.
FIGURE 5.2 Examples of tremolo between two timpani
Dead sticking: Stick does not rebound but remains in contact with the surface.
Rim shot (stick shot): One stick strikes the other, which is held with the tip on the center of the head, and the side of stick on the rim. In an alternate method, the stick strikes down on the head and rim simultaneously. Both sound like the crack of a pistol and are notated with the letters "RS" over the note head.
When notating duration for instruments with little natural sustain, use convenient and easy-to-read note values, as with pizzicato notation for strings. For instruments with more sustain, such as cymbals, indicate precise durations. The letters "l.v." (let vibrate) instruct the performer not to dampen the sound. Another way to indicate that the sound is not dampened is to use a tie extending into space to the right of the note that sustains. Orchestrators should be specific in their notation of rolls for mallet performers on the xylophone and marimba and not assume that long note values will automatically be rolled.
The force of the stroke, point of impact, and material with which the instrument is struck all play a part in the kind of sound produced. Special instructions in this regard should be placed in the score and parts. The harder the implement, the sharper the attack. Typical striking instruments include drum sticks, wire brushes, mallets (wood, rubber, plastic, felt, and yarn) and the triangle beater.
It is important to indicate where on the instrument the mallet or stick is to strike, if other than ordinary practice is desired. The center of a drumhead produces a dead sound when struck; hitting nearer the edge produces a full, more normal sound. Dynamics and timbre vary widely from the center to the edge of any stretched membrane.