Shaun Baxter brings you the first part of his lesson on creating harmony-guitar parts.
As it is based mainly on simple chord forms and straightforward rhythms, our current series on neo-classical rock gives us a good opportunity to look at the various principles and protocols behind creating harmony parts to a given melody. When harmonising a melody, two voices (pitches) may move in three ways in relation to each other. 1) Contrary motion: moving in opposite directions 2) Similar motion: moving in the same direction 3) Oblique motion: one remains stationary while the other moves
Similar motion is the one that is most commonly used in rock music. I’m sure you’re aware that there are signal processors called harmonisers (into which instruments can be fed on their way to the amplifier) that simultaneously generate another note (or notes) a specific distance from the original note (above and/or below it).
Basic (non-intelligent) harmonisers work by generating a second note in response to the first. The time lag between the first and second note is so small that the listener perceives both as being played simultaneously, thus creating a harmony. The user programmes the harmoniser so that the second (harmony) note is a pre-set distance away. For example, if you programme the harmoniser to generate Minor 3rds above the original, the second (harmony) note will always be three semi-tones higher than each note played.
This form of similar motion – where two intervals remain the same distance apart – is known as parallel motion. Octaves, 5ths and 4ths tend to work best with non-intelligent harmonisers; however, unless you are using octaves (the identical note 12 semitones higehr or lower), the second note won’t always be in the right key.
Intelligent harmonisers allow the user to pre-programme a particular scale (G Lydian, for example) and, rather than always generate a note that is a consistent distance away from the original, it will compensate. For example, if we program the harmoniser to correspond to the C Major scale, and ask it to generate 3rds, it will produce a D note each time one plays a B note (an interval of a minor 3rd), but then produce an E note when a C note is played (a distance of a major 3rd). The harmoniser will compensate in a similar manner for any other chosen interval/ harmony with any particular scale of your choosing; however, the motion created by an intelligent harmoniser is still considered to be parallel (in other words, a minor 6th followed by a major 6th is still considered to be parallel 6ths, even though the 6ths are of unequal size).
Although used heavily in rock and pop, certain modes of parallel motion (such as unisons, 5ths and octaves) were systematically avoided in the 18th and 19th century; so Beethoven would probably be spinning in his grave to know that there are machines that exist in order to produce such musical ‘monstrosities’.
Thankfully, we don’t continue to live in such pedantic times; however, the traditional objections to certain forms of parallel harmony do have a practical basis, and are not just rooted in some pompous aesthetic.
Melodically, the limitations of parallel motion are quite easy to observe. For example, if one were to create a parallel harmony for a two-note melody comprising G to B by simultaneously playing B to D, although harmonious and correct within the key of C, we would get two consecutive B notes. This form of repetition can start to sound particularly tedious when played in succession (such as when harmonising arpeggios in parallel 3rds).
To counteract this, one could: Increase the distance (register) between the various
parts (such as moving one or more parts up or down an octave) so that none of the following notes duplicate any of the previous pitches. Avoid parallel motion by applying either contrary motion or oblique motion. Omit certain notes, so that the harmony is implied. Or create rhythmic counterpoint, so that the listener gets a sense of harmony from notes as they are played consecutively, rather than simultaneously.
Regarding a method for establishing harmony parts, you could try any of the following: Playing all of the voicings simultaneous on one instrument (depending on the difficulty of the line). Programming each part via MIDI in a DAW (Digital Audio Workstation) such as Pro Tools, Logic or
Although used heavily in rock and pop music today, certain modes of parallel motion were systematically avoided altogether in the 18th and 19th century.
Cubase, so that you can hear them all played back together. Write the parts out using music-notation software such as Sibelius, Finale or Notion (initially, this will be quicker and easier to see if you can put all of the parts in one stave). Again, each of these types of program will allow you to hear the results as it ‘plays’ the score, generating the results via MIDI. You could, of course, get together with other musicians!
In the following musical examples, we are going to discuss some of the pros and cons of parallel motion. We will touch on some alternative forms (contrary and oblique motion), but will concentrate mainly on ways of applying parallel and similar motion in an appropriate and effective manner.
So far, we have discussed how parallel motion often results in repeated notes when the melody moves in the same interval as the accompanying harmony line(s). Another inherent disadvantage is that parallel motion doesn’t always articulate (relate to) the underlying harmony (chords).