QMidiArp is an advanced MIDI arpeggiator, programmable step sequencer and LFO for Linux. It can hold any number of arpeggiator, sequencer, or LFO modules running in parallel.

Arpeggiator modules produce sequences depending on the notes sent to their input port, which is typically connected to a keyboard or another sequencer.

Step sequencer modules allow you to create simple linear, monophonic and globally transposable sequences similar to the first analog sequencers.

MIDI LFO modules independently produce MIDI controller data of adjustable waveform, time resolution, amplitude and duration.

A Global Storage Tool can store different setups and switch between them at a given time. It allows you to dynamically combine patterns and LFO wave forms.

For each module, an input note filter is available, and the output port and channel can be set independently. QMidiArp can be synchronized to an incoming MIDI realtime clock or as a JACK transport client. Most of the relevant control elements are accessible via MIDI controller through a MIDI-learn infrastructure. QMidiArp also has a log tool displaying the history of incoming MIDI events in colors depending on their type. It has support for JACK MIDI and ALSA MIDI backends. QMidiArp runs on Linux and uses the Qt toolkit. The modules are also available as LV2 MIDI plugins.



  • Programmable arpeggio patterns with preset infrastructure
  • Pianoroll-type display of arp patterns and cursor line
  • Envelope function for chord arpeggios with high polyphony
  • Latch mode or Footswitch for holding notes in arpeggio buffer
  • Keyboard-triggered or -restarted modes for all modules
  • Small input note delay making QMidiArp suitable for live play
  • Random and Groove functions
  • MIDI LFO modules: LFOs have calculated and drawable waveforms, selectable frequency, amplitude, offset, time resolution and length
  • Waveforms can be recorded from a MIDI controller
  • Step sequencer modules: Sequencer can be transposed and velocity-modulated by received notes, sequence can be drawn on the fly
  • MIDI-learnable control of many live-relevant functions
  • MIDI-controllable Global storage panel for Live switching between setups
  • MIDI realtime clock slave synchronization (ALSA MIDI only)
  • JACK transport client synchronization
  • MIDI Event log window
  • Manual pages and i18n support in English, French and German
  • JACK and ALSA MIDI backends
  • LADISH level 1 support
  • JACK Session support
  • NSM support
  • Modules available as LV2 plugins
Software type
LV2 plugin
Software language
Software features
Step/grid sequencer
Frank Kober et al

Recent releases Release Date
QMidiArp 0.7.0 18 May '23
QMidiArp 0.6.7 11 Apr '23
QMidiArp 0.6.6 8 Apr '23
QMidiArp 0.6.5 17 Dec '17
QMidiArp 0.6.4 1 Nov '16
QMidiArp 0.6.3 1 Nov '15
QMidiArp 0.6.2 6 Oct '15
QMidiArp 0.6.1 24 Sep '14
QMidiArp 0.6.0 1 Jan '14
QMidiArp 0.6.0 1 Jan '14