A HARMONIC VIEW OF RHYTHM: PART 3 – ‘How to Actually Use This Stuff’

  • PART 3 – HOW TO ACTUALLY USE THIS STUFF

In part 1 we learnt where rhythm lies on the frequency spectrum, and what that usually means in terms of usage.

We saw in Part 2 how we can see the pulse as our ‘tonal center’, in terms of rhythm. Also how subdivisions and rhythmic detail can give us richer textures/detail on top of our harmonic rhythmic structures.

Here I’ll talk about how to transpose some more ideas we’re quite familiar with in terms of harmony – such as melody, chords & scales – down to the rhythmic level.


WHAT IS A RHYTHMIC MELODY?

A melody in it’s most basic description is simply a succession of notes, or frequencies. In terms of rhythm this is a succession of different rates of notes.

A basic ‘rhythmic melody’, and the equivalent melody if you were to see the 1/4 note pulse ‘rhythmic tonal center’ as Middle C.

A relatively varied rhythm in terms of using different subdivisions, but look at all the space between the relative pitched notes! In terms of pitched melody, it’s not exactly nuanced.

Using more interesting prime subdivisions such as 5s & 7s is a great place to start developing this, as their harmonics (both faster and slower) can give a really rich vocabulary and subtlety.

We can make more interesting ‘rhythmic melodies’ by incorporating these subdivisions. Variety is the important thing! A melody that stays on one note is likely to be dull to listen to (unless you change the harmonic context of that one note…)

As well as variety, it’s useful to think about the qualities that make a melody feel good, satisfying, nice to hear. There are many factors to this, including (but not limited to) patterns/repetition, resolution, contrast, tension and release. Tension in harmony is created when you move to a ‘weak’ note, or one that is at odds with the chord, or even at odds with the whole key. Release and resolution would be coming back to a note that feels very much at home, for example the tonic, fifth or third of the chord/key.

The phenomenon of tension/release has to do with consonance vs dissonance. Consonant rhythms (and therefore harmonies) are ones where the repeating impulses coincide at more regular intervals. So for example, an octave (2:1) is very consonant, as the patterns will meet up every 1 cycle of the ‘2’ side; compared to a major third (5:4) where the patterns will meet up after 4 cycles of the ‘5’ side, or 5 cycles of the ‘4’ side.


WHAT IS THE ‘KEY’ OF THE RHYTHM?

Anyone who’s spent any time looking into afro-cuban and latin music styles will know what the ‘clave’ is, and most again will know that ‘clave’ means ‘key’. This is a great example of this cross-discipline link between harmony and rhythm.

‘3-2’ clave: all other parts of the music will base their rhythms around this underlying ‘key’.

The ‘key’ is an underlying structure that everyone in the music is agreeing on as being a foundation. Sometimes it’s played by someone very explicitly, sometimes more loosely, and sometimes it’s just implied by certain parts played on certain instruments that link up rhythmically with the ‘key’, the clave. It is just the same as a group agreeing to play in C major, and so everyone plays within the boundaries of that set of notes, going outside of these boundaries to create tension and interest.

A rhythmic key change in this general sense of a fixed ‘feel’ could be moving from say feel to , or even from a triplet-based pulse to a duple-based pulse.

A rhythmic key change of a more harmonic sense would be shifting the main pulse to an entirely new one, related to the original pulse. For example a metric modulation where, as an example, triplets in the original tempo become the new ‘root’ 1/4 note pulse in the new section.

In both senses of a rhythmic ‘key’, much like harmonic keys, it can be confirmed via the use of a cadence, and modulated by use of a common ‘pivot’ chord.


WHAT IS THE ‘SCALE’ OF RHYTHM?

A scale, similar to a key, is a set of notes. It could be all the available notes in the key (e.g. the major scale), or it could be a smaller set that sound nice together (e.g. pentatonic scale). Essentially, it’s a palette of colours we can use to compose with.

As we saw earlier, most palettes in terms of rhythm as we know them in western popular music are very limited to just being octaves and fifths. Taking fairly simple polyrhythms we can reveal a wealth of options in ranges where typically you don’t hear many. Here’s a list of some simple polyrhythms and how they fit in between the ‘octaves’ of more widely used subdivisions:

1:1 (crotchet) – 1 note in the space of 1 beatroot
4:3 – 4 notes in the space of 3 beatsperfect fourth
3:2 (1/4 note triplets)perfect fifth
5:3major 6th (VI)
7:4harmonic 7th (b7)

2:1 (quavers/8th notes)root
9:4major 2nd (II)
7:3 
5:2major 3rd (III)
8:3perfect fourth (IV)
3:1 (quaver/8th note triplets)perfect fifth (V)
7:2harmonic 7th (b7)

4:1 (semiquavers, 1/16 notes)root
9:2major 2nd (II)
5:1 (quintuplets) 
6:1 (sextuplets) 
7:1 (septuplets) 

8:1 (demisemiquavers, 1/32 notes) 

N.B. There are more fairly simple polyrhythms that will fit into this list, such as 6:5 (minor 3rd), or 8:5 (minor 6th) which I have omitted here for the simple reason of making a simpler basic scale to work from at first.

Practising through all these would be the equivalent of playing a chromatic scale. As an exercise it can be useful to get to grips with what each one feels like, but more likely you’ll want to find combinations of a few that work together.

For example, try making a melody or improvisation that uses quavers, quaver triplets and 5:2. The 5:2 will create a dissonance/tension that is released when it settles on the more consonant triplets, or even more so on the quavers. This is the equivalent of the melody ’resting’ on the tonic or the fifth of an accompanying chord.

Bear in mind that a lot of the above note rates will be related in terms of octaves, so they will definitely work together but won’t necessarily add anything functionally/any additional harmonic interest (e.g. 1/8 note triplets and 1/4 note triplets will serve the same harmonic function).

Also bear in mind that all of these polyrhythms can and should be not just played as solid rates of notes, but using variety and vocabulary of notes and rests, just as you would with crotchets and quavers. E.g for groups of 5 you could play X(-)X(-)(-) or X(-)xX(-) and so on. As we saw earlier these still serve the function of a group of 5, but we’re giving them a different texture.

As a general rule of thumb, if you want to embellish one of these subdivisions with harmonics of itself, for any that are based in multiples of 2 (e.g. 5:2, 9:4), you can double up the notes and still be locked in with the underlying subdivision (doubling a note in 5:2 has the equivalent of playing some quintuplets). For any that are based in 3 (e.g. 5:3) you would split the notes into 3. 


You said chords can get messy in rhythm? What else can we do to port harmonic elements into rhythm?

To speak about chords, let’s take a simple major triad. Root, major third, fifth. If our root is 1/4 notes, the major third will be a 5:4 polyrhythm against this, and the fifth 1/4 note triplets (3:2). So we have a 3-layered polyrhythm.

Major triad as polyrhythms. Note the 6:5 ratio of the top and middle lines, the equivalent of a minor 3rd interval as you would expect to find between the 3rd and 5th of a major triad.

Polyrhythmic triads can make for difficult listening, though that’s not to say it isn’t possible to make something great.

[henry cowell – fabric ]

Having different voices for different note rates can help to make things less messy, so experiment and see what works.

You could compose something that uses two concurrent note rates, different instruments joining in with either one or the other. This would be the equivalent of a two note harmony. For example, 2 instruments making melodies based in 5:2, another 2 instruments playing in crotchets & quavers.

You could change those note rates over the course of a song to move the rhythmic harmony along. Each ‘chord’ could be a whole section of a piece of music – remember due to where rhythm lies on the frequency spectrum, it lends itself to slower overall changes.

If you kept one note rate the same, while varying the others, this would be the equivalent of the harmony of drone-based music. Except, as we saw earlier, with polyrhythms our perception of which rate is the ‘drone’ is subject to change. So playing with that perception could end up being a fresh twist on an ancient composition style.. either that or just moving into full-blown rhythmic counterpoint – bring on the rhythmic fugues!

If you’ve made it this far, thanks for reading! (And sorry about the headache..) What other ideas can you think of to take inspiration from harmony, and use in terms of rhythm? Leave a comment below, and feel free to ask any questions you may have as well.. and more importantly, I’d love to hear what you end up with if you use any of these concepts!

Cheers-

Jack

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