Melody with drone
A relatively simple type of pitch combination, and one that is common in many traditions around the world, is that of a single line of melody accompanied by one or more continuously sustained sounds of unchanging pitch. The unvarying sounds are called drones, and they give each pitch of the scale a different quality because each scale degree forms a different harmonic combination with the drone or drones.
Writing drones into the score in the same way as other sounds has several disadvantages. One is that it tends to make the drones look more prominent than they would usually be in the minds of either performers or listeners.
Another is that, if the drones are in a different register than the melody, additional space and pitch lines may be needed just for the drones, consuming a lot of space for very little information (although octave transposition may sometimes help; see Wide pitch range).
A third disadvantage is that, when a melody note coincides with a drone pitch, the melody line will be hidden by the drone symbol, making it unclear at times whether there is in fact a melody note sounding in addition to the drone. This happens at the beginning and end of the opening phrase of “Amazing Grace” as played on the Scottish Great Highland Bagpipe. (The complex grace notes in the melody will be omitted from the examples on this page as they are not essential to the points being made.)
One solution is not to write the drones at all in the score, but simply to state what they are at the beginning. This is the approach most often adopted in staff notation of music that uses drones. But this too has its drawbacks if the goal is to represent what listeners actually hear.
Omitting the drones makes the music look different than it sounds, requiring the reader to “remember” the presence of sounds not indicated in the score. As a result, the score fails to capture a feature essential to the aesthetics of drone-based music: the shifting harmonic combinations formed by melody notes and drones together.
To bring out that feature while keeping melody and drones distinct, it is desirable to write the drone sounds into the score but in a different manner from the melodic pitches. This can be done by writing the drone sounds with lines somewhat thinner than those used in the symbols for other sounds of specified pitch (though still thicker than any of the pitch lines). Moments where a melody note coincides with a drone pitch will then be distinguishable by a thicker line superimposed on the one representing the drone.
Admittedly, the proliferation of different line thicknesses is difficult to manage when writing by hand, and though easy to produce using graphics software, it may tax the reader’s ability to distinguish the various types of line by thickness alone. To mitigate these issues, it may be worth using color. Remembering the principle that color is used (if at all) for symbols representing sounds you can hear, the drones will then appear in color as well as the melody.
Theoretically, the red horizontal lines representing the drone sounds should have a thin black pitch line in the middle, since each drone falls on one of the scale degrees. However, that would be redundant if we consider that a drone pitch is practically always one of the pitches of the scale used in the melody it accompanies, so a drone symbol is also a pitch line by implication.
Instead, we can use a pitch line in the middle of a drone symbol only for a drone that falls on the tonic pitch, to distinguish it from other drones. (Actually, the tonic usually is one of the drone pitches, if not the only one - the Great Highland Bagpipes are an exception to the rule.) In this case, the tonic pitch line is drawn the same thickness as other pitch lines to avoid obscuring the drone symbol, though still extended at both ends as usual.
The practice is illustrated here with the tune “Small Coals and Little Money” played on the Northumbrian smallpipes, an English bagpipe that normally uses drones on both the tonic and the fifth scale degree. This time, the length of time for which the drones sound before the melody begins is not specified as it is not considered musically significant.
In monochrome, it becomes less obvious which drone is the tonic, although this information is still available from the extended pitch line at the beginning and end of each system.
Notice how the inclusion of the drone sounds in the notation reveals something of the harmonic relationship between melody and drones. In general, where a melody note either coincides with one of the drone pitches, or is separated from both drones by an interval of two scale degrees, the combination is “consonant”: it sounds relaxed and settled. Where a melody note falls on a scale degree adjacent to one of the drone pitches, the combination is “dissonant”: it sounds tense and in need of resolution.
In “Small Coals and Little Money,” the combinations are consonant most of the time, but a pattern of consonance and dissonance appears if we compare the third beat of each bar. This beat stands out because the melody on all the other beats is identical in every bar except the last. In bars 1 and 3, the two melody notes that fall in beat 3 both coincide with the drone pitches; but in bars 2 and 4 they are both shifted one step lower, creating a dissonant relationship with the drones. This kind of alternation between consonance and dissonance is a vital feature of the style, and justifies a special effort to capture it in the notation (see Relating melody to chords).
Sources of audio
“Amazing Grace” from Scotland the Brave: Highland Bagpipe Classics, performed by Jukebox Junction, Silence Is Golden – OMP CD, ASIN: B00551XBGO, track 3.
“Small Coals and Little Money” from The Northumbrian Pipers Society Tunebook, performed by Richard Butler, Northumbrian Pipers Society cassette tape.