Secrets of the Arpeggiator
Pages: 1, 2, 3

Steppin' Out: Arpeggiation Tips

An arpeggiator is primarily a device for creating rhythmic parts that have an element of motion. When programming an arpeggiator track, you'll probably want to consider adding other elements to the synth preset that add still more motion. There are several ways of doing this:



Stereo delay effects, which are included in many synths, can turn a simple arpeggio into a massive wall of moving notes—listen to "delay.mp3." The delay should be synced to the same master clock as the arpeggiator. (Synchronization is often switched on by default.) I like to set one side of the delay to quarter-notes and the other side to another value, such as dotted eighths.

A synced LFO can be an excellent source for modulating filter cutoff or an oscillator waveform while the arpeggiator runs. If your synth has several LFOs, set each to a different rhythm value and use them to modulate different parameters.

A "trancegate" effect, which switches the sound on and off in a rhythmic way, works extremely well when combined with an arpeggiator and a delay. If your synth doesn't have this effect, you may be able to apply it in the host sequencer. In this case, you'll also want to put the delay effect in the host, because delay generally works better when it's after the rhythmic gate in the signal path.

Now let's look at some performance techniques.

Correct the timing. When recording a MIDI sequencer track that will play the arpeggiating synth, it's almost always desirable to quantize the note-ons so that they start on the beat. This will keep the arpeggiator in sync with the rest of the music.

Arpeggiate your fingers. It can also be useful to roll your chords slightly when recording the track. With some arpeggiator patterns, the note order makes a difference. Though it may not be intuitively obvious when you look at a piano-roll edit window, even after a chord is quantized so that all of the notes start on the same clock tick, they're still listed in the track data in a linear order, one note at a time. Whichever note you played first will still be first, even after quantizing. (Unfortunately, some arpeggiators lack a reset-on-stop feature. If the pattern doesn't reset, then the first note heard will depend on what step the pattern had reached when you last stopped the transport in your host program.)

Starve the delay. If you're using a rhythmic delay, you'll probably want to end the held chord a beat or so before any harmony change, to give the audio in the delay line time to "clear out." This will help ensure a clean transition to the new chord.

Shift the beat. By pressing and releasing single keys within a chord while the arpeggiator plays, you can change both the melodic shape of the arpeggio and its rhythm. Depending on the pattern or mode you've chosen, the rhythm will be affected because more or fewer notes are being arpeggiated. For instance, if a four-note chord generates an arpeggio that lasts for exactly two beats, adding a fifth note will cause the pattern to be two and a half beats long.

Drum up (and down). Don't think arpeggiators are just for pitched sounds; you can get some very interesting grooves by arpeggiating a drum kit patch, in which each note triggers a different drum sound.

Multiply the effect. Some instruments allow several arpeggiators to run at once. The way to set this up will differ from one instrument to another, but in most cases the instrument will be in multitimbral mode. Different presets will be assigned to the layers of the multi. The arpeggiator programming may be handled in the presets, or it may be handled within the parts of the multi. In any case, such a setup can create massive and hypnotic walls of rhythmic sound. Adding modulation to the layers (stereo panning, for instance, and filter cutoff sweeps) will cause the arpeggiations to weave in and out of one another.

What Goes Up Must Come Down

The insistent rhythm of an arpeggiator is best deployed in highly electronic styles, from ambient new age to 1980s synth-pop. In theory, an arpeggiator doesn't do anything that you couldn't do with your fingers if you were willing to take the time to record and edit a sequencer track. But setting up an interesting arpeggio pattern first and then experimenting with chord voicings is a lot faster than reprogramming a MIDI sequence track one note at a time.

Also, the factory patterns included with many arpeggiators can be a source of inspiration. Just lay your hands on the keyboard, and you may find that the arpeggiator has fired up your imagination.

If you're up for it, get down with it.

Audio Examples

To demonstrate some of the possibilities of arpeggiators, I chose U-He Filterscape VA, whose arpeggiator you can see in Figure A. This synthesizer is one of the three plug-ins included in the Filterscape package; the other two are filter effects. After downloading the demo version, which produces occasional noise bursts until you buy the product, you can install these example presets I made (12KB Zip file). In Windows, you should copy them to C:\Program Files\u-he\Presets\FilterscapeVA.

Fig. A: Filterscape Arpeggiator

Figure A. The U-He Filterscape VA arpeggiator has pop-up menus for rhythm value, gate time (shown), number of notes to be included in that step, and note transposition. The strip along the bottom outputs a line of controller data.

 

"Basic Arp" provides a very simple arpeggio in "up" mode. The clock moves in steady 16th-notes, and all of the gates are the same length. The only extra programming trick used here is a two-measure LFO sweep of the filter to add a little animation:

In "ArpAccents," the length of the pattern is five notes. I used three different gate lengths. In addition, Filterscape's "Arp Modulator" output modulates both the oscillator waveform and the filter cutoff to provide accents. If you play this arpeggio while holding anything other than five notes on the keyboard, you'll hear the rhythmic pattern shift across the pitch pattern:

"Arp Delay" uses the same underlying arpeggiation as the Accents preset, but the stereo delay line has been turned on, creating a much more animated sound. Note that the arpeggiator is still playing only one note at a time:

This patch becomes even more interesting when you click the ON button in the parametric EQ section, located to the left of the central wheel, adding tone-shaping:

"Arp Rhythm" uses two of Filterscape's more specialized features. One of the steps is set to an eighth-note rather than a 16th, so that the seven-note pattern lasts for two beats. In addition, two of the steps play three-note chords rather than single notes:

Finally, "Arp Steps" uses the arpeggiator as a step sequencer. If you hold one note, you'll hear a dominant seventh chord pattern. Holding more than one note at a time will create a more complex and probably less interesting pattern:

Jim Aikin writes about music technology for a variety of publications and websites. His most recent books are Power Tools for Synthesizer Programming and Chords & Harmony.

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