One of the more popular terms in percussive vernacular, a drum roll (or simply a roll) refers to a group of notes being played at an extremely fast rate. While fairly simple in concept, there are a few things to consider when notating them. In general, rolls are written with three dashes cross through the stem:
If we follow the logic that three dashes is equal to three times the written value, this would come out to one beat of eight 32nd notes. At a fast enough tempo, the only option is to roll. At a slower tempo, the actual 32nd notes could indeed be played, though if that is the desired effect, it’s important to make this clear by not using the roll notation. A percussionist is almost certainly going to assume that a roll is desired when seeing this (more on this below).
Regardless of speed, I would highly advise against writing anything faster than a quarter note when writing rolls, unless the duration is intended to be less than that that, or if it is ending on a partial under than the main beat. Notating rolls in a way such as the below example looks very sloppy and should be avoided.
Aside from looking bad, a percussionist will most likely use as many strokes in a roll as they deem necessary to make the best possible sound. Notating a specific number of strokes will almost certainly be ignored.
An open roll is a roll that allows every individual stroke to be heard. Unless being used in a rudimental drum part, it’s not safe to assume that a roll should be played as open. To make sure this happens, text instruction should be provided on the part. Another option would be to notate the desired rhythm, and if done so at a fast enough speed, the player’s best option would be to play as an open roll.
Buzz rolls, or “closed” rolls, are used in many situations, and are the predominant roll of orchestral music. This type of roll produces a sustained buzzing sound, with the strokes of the sticks so close (or closed) together that, when executed well, disguises when one hand is taking over for another. Buzz rolls are often time played on a context-based assumption (like orchestral snare drumming), though there is a way of making it more clear: the “z” stem.
This notation is reserved for buzz rolls, alleviating any question of what style should be used. While mostly reserved for instruments such as snare drums and toms, it can be employed elsewhere. Which leads me to…
Timpani, Bass Drum, and Cymbals
Unlike the aforementioned drums, a roll on timpani, bass drum, or cymbals is assumed to be done with single strokes, with the actual speed of the roll being determined by variables such as dynamic, pitch, instrument size, and mallet hardness. In most cases, the goal is to create a smooth, sustained sound. That being said, this isn’t the only option. For example, Elliot Carter does specifically call for a timpani buzz roll in some of his work. There’s nothing particularly odd about this, but the important takeaway is that it is very clearly notated with the “z” stem.
In most cases, these rolls are notated using the standard tremolo notation. Note that the trill (tr~) marking is considered outdated.
Mallet rolls should only use the standard stems. The only practical option for mallet rolls is single strokes, though it’s worth noting that a composer could make a note to the player to roll very slowly, as fast as possible, etc. Buzz rolls are mostly impossible on mallet instruments. The lack of bounce from a key combined with the very top-heavy nature of a mallet will make an attempt at a buzz roll sound much more like a dead stroke.
Ending a roll
It’s helpful for a roll to have a notated ending. Having a roll simply stop is different to having a note that functions as a sort of off switch. See the below examples:
In example A, it is very clear that a buzz roll should be played on the downbeat, with an unrolled note being played on the upbeat to end the roll. In addition to this, the tie clarifies that the first note should go all the way until the second, rather than just being pressed into the head in a dead stroke-esque manner. Example B has a rest on the upbeat, implying that the roll should end sometime before that moment. Neither of these are right or wrong, however it’s important to understand the difference so as to best convey your intentions.