StepPolyArp Unit

Step Polyphonic Arpeggiator / Sequencer

App & Audio Unit MIDI effect for iPhone, iPad with iOS 11.0 or later

"StepPolyArp Unit" is a real-time polyphonic and polyrhythmic MIDI step arpeggiator and step sequencer. It can be used as a standalone application or an Audio Unit MIDI effect plug-in.

The application and the plug-in can operate as a step arpeggiator by automatically generating melodic patterns from played notes or chords, or as a step sequencer that doesn't require MIDI input to play.

Download on the AppStore

Download the documentation


  • Default velocity, modulation, pan, volume, aftertouch, and pitch bend steps controller
  • Customizable steps controller MIDI setup
  • Arpeggiator and sequencer conform to the selected scale
  • 6 arpeggiator modes
  • 1 random mode
  • 1 chord mode
  • Random patterns creation
  • Presets manager
  • "Program Change" support
  • Native iCloud support
  • "Files" application support
  • Full support of "Split View" and "Slide Over"
  • 128 Undo / Redo levels
  • Copy and paste
  • Lockable keyboard (latch mode)
  • Standalone application and Audio Unit MIDI effect plug-in
  • Arpeggiator and step sequencer mode
  • 1 to 32 steps programmable matrix
  • 11 configurable transposition lines
  • Polyrhythmic lines
  • 16 patterns by preset
  • Automatic chaining patterns
  • 8 octaves resizable keyboard
  • Multitasking
  • Sample-accurate timing
  • Internal sound bank
  • Tap tempo
  • Receiving MIDI from external MIDI sources
  • Receiving external MIDI sync (MIDI clock)
  • Ableton Link support
  • Internal routing of inputs, outputs, and MIDI sync
  • Send MIDI to a virtual port that can be used as MIDI input by other "Core MIDI" compatible applications

Audio Unit MIDI effect plug-in included

The Audio Unit MIDI effect is compatible with: Cubasis, Audiobus, AUM, apeMatrix.


Full MIDI connection support

  • Virtual "Core MIDI" connections between applications
  • iOS compatible MIDI interface
  • MIDI over Wifi
  • MIDI over Bluetooth
  • Ableton Link (sync and transport)
  • Audiobus (MIDI, transport, state saving)

Play in time with Ableton Link

StepPolyArp Unit includes Ableton Link technology that synchronizes beat, phase and tempo of Ableton Live and Link-enabled iOS apps over a wireless network.



StepPolyArp Unit Introduction

A video introduction to StepPolyArp Unit. The presets used in the music are "Wonderland", "Overture", "Poly Percs", "Leader", and random generated patterns for the melodic part.

SoundPrism Pro and StepPolyArp by ‪Audanika

This tutorial shows how StepPolyArp can be controlled via SoundPrism: MIDI notes are sent from SoundPrism to StepPolyArp, StepPolyArp generates an arpeggio and sends it back to SoundPrism.

Controlling an Oberheim FVS by Logan Mannstrane

The StepPolyArp iPad application hooks up wirelessly to a Windows or OSX computer. I currently have the StepPolyArp app talking with Logic Pro that then drives a Doepfer MCV24 to go from midi to CV and Gate. The Oberheim is being triggered in Unison for all 4 Voices on every step.

StepPolyArp on Apple iPad triggering Moog Little Phatty by Luis Duran

This time I sent the sequence live to a MOOG Little Phatty thats running thru a Freqbox, Ringmod, and a Bass Murf which in turn is passing thru the DAWs Direct monitor live with a u-he Filter with some delays and verb. Access Virus TI Polar is playing some pads in the back.

DSI Tempest with StepPolyArp by Linforlk

DSI Tempest with iPad (StepPolyArp). Only Sound DSI Tempest (Analog).


Presets can be synchronized to iCloud and available on all devices

"Want to get arpeggiating in Logic Pro? There's two main ways to set this up inside Logic... but wait, with an iPad you can get hands-on thanks to StepPolyArp app. Darren Burgos shows how."

Darren Burgos - macProVideo

"I really love this Arpeggiator... StepPolyArp is really really well thought out. You can create a Pattern (16 patterns available / Preset) very fast, create Accidents, Random, Automations (Velocity, Modulation, Volume, Pan, Aftertouch & PitchBend). 11 "tracks" are available on the grid (you can set their MIDI channel independently). Read the specifications at the end of this post. Watch also the video demo... A Killer App!"