QMidiArp is an advanced MIDI arpeggiator, programmable step sequencer and LFO for the ALSA sequencer. 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 one 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.

For each module, an input note filter is available, and the output port and channel can be set independently. Since the modules use a common sequencer queue, they are automatically in sync with each other. QMidiArp works with an internal tick resolution of 192 ticks per beat. The queue 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. QMidiArp is based on the Qt toolkit.