Paul’s Tech Talk – Exploring Arpeggios part 1: The Power of Illusion

- Posted March 16th, 2018 by

Hello beautiful people and thank you for reading Paul’s Tech Talk on The ChipWIN Blog! It’s been a while since I’d last whipped out a good ol’ techy article so I decided to make this one extra special. Today we’re going to delve into one of my all-time favourite aspects of chiptune production: Arpeggios!

Most of you probably know quite well what an arpeggio is, and why it’s widely used in Chiptune music. So in this article, I will try to dig a little deeper, examine closely how they work and what they can do, and experiment with some more advanced techniques to unleash their amazing potential.

Let’s dive in!

I. Concept

1. The Arpeggio Paradox

Let’s start by looking at a few basic definitions, and see what these tell us.

Arpeggio:

  • A chord broken into a sequence of notes” [Wiktionnary]
  • “The tones of a chord, played in succession, and not simultaneously” [Merriam-Webster]
  • “The playing of the notes of a chord, in quick succession instead of simultaneously; or a chord so played” [Collins]

I’ve also resisted posting the Urban Dictionnary definitions which are more funny than actually informative, and a bit of a jab towards guitar players.

An arpeggio is, in conclusion, sort of a missing link between chords and melodies. It shares characteristics and differentiates itself from both at the same time. It’s a chord, but broken into its building blocks, which can no longer be played simultaneously. It’s a succession of notes, but quick enough not to be considered a melody.

Piano pieces like the infamous 3rd movement of Beethoven’s “Moonlight” Sonata“, or Chopin’s “Ocean” Étude [the sheet music of which you can see in the introduction picture] demonstrate how arpeggios can become the cornerstone of a piece, serving both the harmonic and rhythmic structure, and the melodic progression at the same time.

In the scope of Chiptune however, where polyphony is one of the major limitations, arpeggios are often made to fill the role of chords altogether. Even though polyphony is very limited in LSDJ, with a maximum of 3 tonal notes being actually played at the same time, the speed at which notes are successively played in a single channel goes well beyond the reach of the fastest virtuoso musicians. Fast enough in fact, that the illusion of an actual polyphonic chord can indeed be sustained.

2. Speed and the Illusion of Polyphony

Many production and design techniques in Chip music stem from the idea of a successful illusion. No wonder we call them “tricks”, it’s exactly what they do. A fast-pitched triangle wave takes the guise of a boomy Kick Drum. A quick succession of sharp and short noise bursts evoke the cracking sound of a Clap. Hell, even pulse waves with no more than 3 basic different shapes can successfully be mistaken for formant synthesis, and trick your brain into [hearing   actual    lyrics]. And most of it has to do with either timing or speed.

A standard 808 CLAP sample consists of four quick successive hits before tailing off.

Music turbonerd Adam Neely mentions in this video that the threshold around which we begin to perceive two consecutive sounds as simultaneous sits around one tenth of a second. 16th note sextuplets at 120 bpm last about a twelfth of a second each, so that’s a good “musical” threshold to consider, in a way. There’s a good reason why arpeggios that are quick enough convey the illusion of polyphony. When notes are too short for our brain to separate them and consider them individually, what we perceive is not the tones, but the harmonic interval between them.

However, once again due to the limitations and inherent harsh sonic qualities of Chiptune sound hardware, residual noise, pops and clicks are bound to happen between your arpeggio notes. This means there is also an upper threshold around which notes will be played too fast to actually be recognized as the building tones of a chord, and where noise will begin to overpower harmony.

In the following clip, Tempo spans from 40 to 255 bpm in LSDJ. At the highest speed, the entire 8-note arp cycle ends up shorter than 100ms, which is probably why the arp starts sounding a bit garbled towards the end.


As such, finding an adequate speed for arpeggios is a determining factor in sustaining the illusion of polyphony. But there are many other elements and characteristics one can use to shape and sculpt arpeggios, so let’s examine those now.

 

II. Anatomy and Application of Single-channel arpeggios

The following parameters and their effect function with arpeggios of 3 or more notes. If you’re into using groups of two, or four and more, don’t worry! I’ve got you covered in the next part!

1. Standard Motion Patterns

UPWARD

  • Swelling, soaring sensation
  • Vowel progression: “OO” > “OH” > “AH” > “EE”
  • From darker to brighter tones
  • The first note is the lowest, making the attack smoother

As a result, upward arpeggios blend reasonably well in the background. The last note of your arp however will be the highest, and the one that stands out the most, so trying out different chord inversions can help if you feel it sounds a bit too jarring and out of place with the rest.

DOWNWARD

  • Conclusive sensation, closing down
  • Vowel progression: “EE” > “AH” > “OH” > “OO”
  • From brighter to darker tones
  • First note is the highest, making the attack sharper.

The starting note, because it’s higher in pitch, will act as the attack and be accentuated over the rest just by being there. As a result, the periodicity of downward arps will be a crucial factor, as it will create a clear-cut rhythmic outline. Here, choosing an adequate chord inversion is even more important.

UP THEN DOWN/DOWN THEN UP

  • Upward and Downward are juxtaposed, qualities of both are present
  • Sounds more circular and cyclical
  • Up then down blends, Down then up outlines rhythm further
  • Middle notes are repeated twice as often

The middle notes of an up/down arp stand out harmonically, due to their increased presence and proximity, which makes them sound more sustained and continuous. They are however blended in rhythmically, letting the extremity notes pop out.

This Up&Down arp is symmetrical, but don’t hesitate to try things out where the upward and downward notes are not the same !

These are some the most basic patterns you can shape your arps around. Don’t hesitate to switch them around, blend them together and experiment. I could go into detail with other irregular patterns like the “Thunderstruck” arp, or spanning arps across several octaves, but this article is already way too wordy, and I want you to try them out for yourself as well. Pip, pip. There is however, one last single-channel technique I want to blab about before going on.

2. Cross Patterns

CONCEPT

The following section concerns arpeggios of four notes and more.

Cross patterns are in my opinion very useful and often overlooked. Instead of juxtaposing up and down patterns, we actually combine and blend them together to create something different yet.

Let’s consider a basic upward arpeggio for Cmaj7: C, E, G, B. A cross-pattern version of this arp would be: C, G, E, B. Instead of being a succession of 3rds, we emphasize two 5ths; C-G and E-B. The upward motion is broken in the middle of the pattern, even though the first and last note remain the same. The resulting arp retains a general upward quality, but its straight flow is broken, which actually helps blend it together a little tighter thanks to the shift in intervals.

1: Regular Upward Cmaj7 2: Cross Pattern Upward Cmaj7 3: Same pattern, 5ths highlighted

You can now play with variations of this pattern, like its descending version B, E, G, C, or even wilder stuff like C, B, E, G, which is completely spread apart. Try some of those yourself and see if you like what you hear!

Now you must be telling yourself that it’s a bit of a detail-oriented thing and that you’d rather be focusing on writing than figuring out the perfect arp pattern for that one bar, but let me tell you, cross patterns (or whatever their actual musical name is) can prove very useful in some specific cases, namely with 7th chords.

APPLICATION: BLENDING TOGETHER SMALLER INTERVALS

Let’s consider our upward Cmaj7 again: C, E, G, B. Let’s say you want the 5th (G) to really pop out, you can voice your arp like so: B, C, E, G. Now your high G really stands out, but the B and C are sort of blurred together. There’s only one semitone between these notes, so at high speeds, they sound more like a pitch bend than a chord and that can mess up how your “chord” holds itself together.

If we choose to keep this voicing but use a cross pattern: we end up with the following arp: B, E, C, G. The minor second interval of B and C is cut across by E. You retain the same voicing, your high G still stands out, and by separating B and C, we manage to make the chord sound tighter and more balanced. The minor second interval ends up sounding like a more convincing part of the “chord” when it’s separated.

1: Regular Upward Cmaj7 2: Inversion with problematic juxtaposition of B and C 3: Cross-pattern with separated B and C

3. Periodicity

As said above, some specific arp patterns will act as rhythmic accents as much as harmony. The best example of this effect happens with a downward arp, where the highest note will be at the start of the cycle, and sharpen the attack.

Consider a downward A minor arpeggio: A, E, C, A. If one cycle of the arp lasts exactly as long as,  say, a 16th note, you can create a strong binary, square feel to your beat thanks to the arp’s sharp attack. On the contrary, if you want your arp to just be there for harmony, choosing an upward pattern and a ternary or uneven period in a binary track can help it blend right under. Last example, using a ternary period with a downward pattern in an otherwise binary track can make it sound very bouncy and polyrhythmic.

Different combinations of beats, arp cycle lengths and arp patterns will all achieve different results, and it’s now up to you to try them out!

For more examples and tips on how to harness the timing of your arpeggios, feel free to refer to my tutorial video on Grooves! There’s a specific part where I show off some of this stuff in a more concise and illustrative manner.


I’ve only talked about note patterns and times in a single channel so far, and the range of what you can achieve only with this is already mind-blowing. But in LSDJ, you have an entire arsenal of commands and effects to apply if you want to spice up your formula further, be it to blend them in or enhance them. I just think it’s important to build a strong base, and that these characteristics are too important to fall under the radar.

Thanks for sticking with me this far! In the second part of this article, I will really show you how to unleash the power of arps in LSDJ, with some advanced dual-channel techniques.

See you soon!

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