An arpeggiator (arp for short) is a sequencing tool found on most synthesizers. In its simplest form, an arpeggiator replicates whatever you play into a repeating pattern (usually an arpeggio). The repeated notes can be set at specific speeds and note lengths to create the desired effect.
For example, if you hold down one note on the keyboard when you have the arpeggiator switched on, you’ll hear a looping pattern based around different pitches of that note. You can see how quick and easy it is to create complex sounds by simply playing more than one note.
If you played a three-note chord, the arpeggiator would then play the three notes in a sequence. The sequence of notes is controlled by choosing one of the available mode options, common modes are “Up”, “Down”, “Up and Down” and sometimes a “Random” mode is offered.
Using these standard sequence options can give you some dynamic melodies and basslines from playing just a single basic chord, combined with the speed and note length settings, you’ll be surprised at how much the arpeggiator can help you push your music further.
A latch function is a useful addition that can be found on some synthesizers, this useful option allows the user to play the note(s) just once and the arpeggiator will continue the pattern until another note or chord is played, making life and the process that little bit easier.
Nowadays, arpeggiators have many advanced settings to give users even more control. Often found in sequencing software, they are capable of creating complex patterns by allowing the user to step through notes or even play more than one arpeggio at a time.
Other available options vary from synth to synth, some give you the option to set out various octave ranges making the sounds more diverse. Polyphonic patterns are available in some synths which allow for multiple notes and chords to be played at the same time.
As you can see, arpeggiators give you the capability to create some really complex and progressive synth sounds with very little effort. It’s a simple yet powerful tool if used in the right hands.