An arpeggio is the notes of a chord played one at a time instead of all at once. An arpeggiator is the tool that does this for you: hold a chord and it cycles through the notes in a pattern, in time with your track. Here is what an arpeggiator does, the controls that shape the pattern, and how it differs from a sequencer.
Works in any DAW, with any synth or sound, whether the arpeggiator is built into your instrument or sits in front of it. Nothing here needs a particular plugin.
An arpeggio is the notes of a chord played one at a time instead of all together. Take a C major chord, the notes C, E and G. Play them all at once and you hear a chord; play them one after another, C then E then G, and you hear an arpeggio of the same chord. It is the same notes, spread out in time rather than stacked.
Because the notes come from a chord, an arpeggio is sometimes called a broken chord: the chord is broken apart into single notes. The word comes from the Italian for playing like a harp, which is roughly what a harpist does when they sweep across the strings one at a time. Nothing about it is new or electronic, and it is one of the oldest ways to state a chord. You hear it across classical music, fingerpicked guitar parts and pop alike, long before any machine was doing it.
Any chord can be arpeggiated, so a chord progression hands you a ready run of arpeggios, one per chord. If you want somewhere to start, our guide to writing a chord progression walks through building the chords you would then arpeggiate.
An arpeggiator takes a chord you hold down and plays its notes one at a time automatically, in time with your tempo. Hold three notes and it steps through those three over and over, in an order and at a speed you set. Let go, change the notes, and the pattern immediately follows the new chord. You supply the harmony by holding the chord; the arpeggiator supplies the rhythm and the order.
So an arpeggiator is doing something a player could do by hand, playing the notes of a held chord in sequence, except it does it perfectly in time and keeps going for as long as you hold the keys. Most sit on a keyboard or a synth, or as a small tool placed in front of one, and they listen for whatever notes are down at that moment. Add a fourth note and the cycle grows to four; take one away and it shrinks. This is the heart of it: the arpeggiator has no notes of its own, it only rearranges the ones you are holding.
Fast, steady arpeggios are a signature of electronic music. Trance is built on them, often a bright run at a 1/16 rate carrying through much of the track, and synthwave and a lot of EDM lean on the same effect for their driving, hypnotic top lines. The reason is simple: an arpeggiator turns one held chord into constant motion, which is exactly what those styles want. Our guide to making trance goes into how that arp sits in the arrangement. You also hear arpeggiators well outside dance music, in pop, film scores and game music, anywhere a part needs to shimmer and move without a player working at it the whole time.
The main controls are the rate, the direction, the octave range and the gate, with swing on top for feel. Rate sets how fast the notes cycle, usually locked to a note value like 1/16. Direction sets the order they play in, such as up, down or up and down. Octave range spreads the pattern across more octaves. Gate sets how long each note sounds. Between them, these turn one held chord into very different patterns.
| Control | Typical setting | What it does |
|---|---|---|
| Rate / Speed | Synced to a note value, 1/8, 1/16, 1/32 | How fast the notes cycle; synced to tempo so it stays in time |
| Direction / Mode | Up, down, up-down, random, as played | The order the held notes are played in |
| Octave range | 1 to 4 octaves | Repeats the pattern up an octave or more for a wider span |
| Gate / Note length | Short to long, set as a percentage | How long each note holds; short is plucky, long is more connected |
| Swing / Shuffle | A small percentage | Nudges every other note slightly late for a looser feel |
The rate sets how quickly the arpeggiator moves from one note to the next, and it is almost always synced to a note value rather than a free speed. Common choices are 1/8, 1/16 and 1/32; a 1/16 rate plays sixteen notes per bar in common time, which is the busy, driving speed most trance and EDM arps use. Because it is locked to the tempo, the pattern stays in time with the rest of the track however you set it, and it follows the song if you change the tempo later.
The direction, sometimes called the mode, decides the order the held notes are played in. Up runs from the lowest note to the highest and repeats; down runs the other way; up and down, often written up-down, climbs then descends; random picks the notes in no fixed order for a more unpredictable feel; and an as-played or order mode plays them in the order you pressed them. This one control changes the character of the pattern more than any other, so it is usually the first thing to try.
The octave range makes the arpeggiator repeat the pattern in higher octaves before it loops. Set it to one octave and it uses only the notes you are holding; set it to two, three or four and it plays those notes, then the same notes an octave up, and so on, before returning to the bottom. A wider range gives a bigger, sweeping pattern that covers more of the keyboard from a single small chord.
The gate, or note length, sets how long each note sounds before the next one starts. A short gate leaves space between the notes and sounds plucky and staccato; a long gate lets each note ring closer to the next for a smoother, more connected line. It is an easy way to change the feel without touching the notes or the rate.
Straight arpeggios can feel rigid, because every note lands exactly on the grid. A little swing, also called shuffle, nudges every other note slightly late, which loosens the pattern and gives it some human bounce rather than a stiff, machine-even run. As with most swing, a small amount goes a long way, and too much starts to sound heavily shuffled.
An arpeggiator builds its pattern from the chord you are holding right now, while a sequencer plays a fixed set of notes you programmed in advance. Change the chord under an arpeggiator and the pattern changes with it, because it only ever plays the notes you are holding. A sequencer plays the same notes it was given whatever you do, because those notes are written into it, not taken from your hands.
That difference is the whole distinction, and it decides which one to reach for. An arpeggiator is fast and follows your harmony: hold a new chord and you instantly get a new pattern in the same rhythm, which makes it easy to run an arp across a chord progression. A sequencer is fixed and exact: you place each note where you want it, so you can write a melody or a bassline that does not depend on what you are holding, but you have to program every note. Many tracks use both, an arpeggiator for the moving chord part and a sequencer for a set bassline or lead.
An arpeggiator plays the notes of a chord you hold, in order and in time, and follows you when the chord changes. A sequencer plays a fixed pattern you programmed, the same way every time. Same idea of notes in sequence, but one reads your hands and the other reads its own memory.
Everything above is something you can set up by hand in almost any DAW, and it is worth knowing how each control shapes the pattern. The slower part is the writing itself: finding a pattern that fits your chords and getting it into the track as notes you can still edit.
REHEAT is a writing tool that generates arpeggiated and melodic patterns for you. Find a pattern you like and you have two ways to use it: drag the MIDI straight onto a track in your DAW, or play it live through your own synth with the REHEAT MIDI DRIVER. Either way the notes are yours to keep, to change the key, the sound or the timing later. It runs as an Audio Unit, a VST3 and an AAX.
That is the point of writing the part rather than printing the audio. An arpeggiated line is worth more as notes than as a recording, because the notes survive every later decision about the sound and the arrangement.
Free to hear in the browser, no signup. Everything above still works by hand in any DAW too, which is rather the point of writing it down.
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