Understanding the Art of Arpeggiators

Arpeggiators are perhaps one of the most straightforward and most audibly recognizable sequencing tools available. They originated in the early days of hardware synthesizers. In essence, an arpeggiator is a very basic real-time sequencer that takes a chord as an input and turns it into an arpeggio. In other words, it automates the sequencing aspect of some sounds. It operates a bit like a gate sequencer but gives you way more control over the parameters of each note in the sequence. The arpeggiator in FM8 is a monster.

It effortlessly generates exotic, unimaginable textures. As an introduction, check out this basic pattern the arp generated with just one note on a percussive, tube-like sound.  

 

In the first place, FM8's arpeggiator consists of 5 parts: the PATTERN editor, the GLOBAL controls, the REPEAT MODE menu, the TIME resolution window, and the EXPRESSION window.  

1. The Pattern Editor 

 

Rows (top-down)

• Step Number: a visual aid. shows where the arp is in its cycle
• On: for programming rhythms, click boxes to enable "note-on" for that subdivision, consequently
• Tie: for interpolating enabled notes and syncopating/articulating. Tying one note to the next will, therefore, turn off the second note on the message.
• Accent: for emphasizing particular notes and creating dynamics
• Note order: Tells FM8 how to handle simultaneous note on messages (voices). There are three ways….
  1. All: all pressed notes will be triggered by that step
  2. Rdm: chose a random note out of the chord for that step
  3. 1 - 32: means the lowest pressed note will be triggered by steps numbered 1, the next lowest pressed note will be triggered by steps numbered 2…, etc. I will delve into this topic further in the next section when I talk about repeat modes.
• Octave: transposes the pitch of the step-up/down by multiples of 12 semitones.
• Transpose: shifts the pitch of the triggered note up/down by the selected number of semitones.
• Left and right arrows: shift the pattern backward/forward one step.

Columns (left to right)

• Reset: reloads the default settings for that row
• Rnd: randomizes the settings for that row 

2. Global Controls

• On: enables arpeggiator
• Copy: copies the pattern and settings
• Paste: loads the copied pattern and settings into a new instance or over the current settings
• Drop-Down Menu: contains preset arp settings to browse and modify
• Save: for overwriting presets (select a preset as the location) or saving a custom set (select user).

3. Repeat Mode Menu

   

• Hold: Sustains the arpeggio after lifting the key until pressing a new key. Therefore, this tool allows you to focus on the sound parameters without holding a key down throughout the process.
• Down: Inverts the note order such that #1 triggers the highest held note, #2 triggers the following highest note… etc
• One Shot: In this mode, the pattern will play through once after note triggering. It is also ideal for non-looping motifs. Also, it is most effective with key sync on. When disabled, the pattern runs freely and constantly.
• Key sync: tells the pattern to reset to step 1 each time a note is played. Ideal for preserving a repetitive theme.
• Tempo Sync: links FM's clock to the DAW's clock such that the pattern can be subdivided into musical divisions that are accurate to your song.
• Repeat Mode Menu: This is where things start to get complex. The warp menu determines how FM8 will order held notes when there are more available voices (note numbers) than notes held. For example, if there are eight available voices and you press C, D, and E simultaneously….. the remaining voice numbers (4-8) could be satisfied in the following ways….

1. Wrap: notes will play in the same order until all eight steps run out. (CDE, CDE, CD)
2. Wrap+: transposes the remaining voices up an octave (C1D1E1, C2D2E2, C3D3)
3. Wrap-: transposes the remaining voices an octave (C1D1E1, C0D0E0, C-1D-1)
4. Ping: pattern returns in the opposite direction without repeating endpoints. (CDE, DCD, ED)
5. Pong: pattern returns in the opposite direction, repeating endpoints (CDE, EDC, CD)
6. Last: the last note pressed will be repeated for the remaining voices  (CDE, EEE, EE)
7. First: the first note pressed will be repeated for the remaining voices (CDE, CCC, CC)
8. Random: chooses from pressed notes at random for the remaining voices (CDE, CED, DC)
9. Pause: the remaining voices will be silent (CDE, ---, --)

As you can hear for yourself, my patch has seriously improved by simply experimenting with the repeat modes and note order on a C minor triad with 5 available voices (note numbers). Remember, it doesn't sound like a C minor triad when arpeggiated because I've transposed several notes. Furthermore, notice the steps marked random trigger a random note out of the chord, and the steps marked all trigger the whole chord.  

   

4. Time Resolution Window

  In short, this window determines the speed at which the pattern plays back in BPM. In addition to this, you can also choose the best value of each step.  

1. Note Length: Of course, this determines the global duration of triggered notes. (staccato or legato)
2. Shuffle: Accordingly, this offsets the grid quantization by a certain amount. Creates a swing/trip-hop feel.

Given these points, check out the same patch with shuffle turned to about 3 o'clock.  

   

5. Expression Window

 

1. Vel: enables velocity sensitivity
2. Velocity: determines how much speed is on the level.
3. Accent: determines how noticeably accented the accented steps are
4. Split: divides the keyboard into 2 sections, arpeggiated and non-arpeggiated - defaults to the high-range being arpeggiated.
5. Bass: when enabled with the split, the low range of the keyboard will be arpeggiated, and the high range will not be
6. Learn: click to map the cutoff point for the split. Or, type in a note name in the box to its right.

All in all, If the soft synths and sequencers you use contain arpeggiators and pattern generators, you should now be in a better position to exploit their capabilities for your productions. Also, you can feed one arpeggiator into another or even use the arpeggiator to trigger less obvious instruments such as sampler or drum machines. This is an excellent way of generating exciting rhythm patterns quickly and coming up with new ideas.   To conclude, check out my complete patch with split parts and some accompaniment.