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User Guide
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What is it?

GENPO is the GENeral Purpose Organ. It replicates the essential features of any pipe, theatre, or reed organ.

GENPO reads a description of an organ (a .org XML file) and presents a suitable user interface for operating that organ. There are a number of high quality organ SoundFonts freely available and the .org file maps the stop sounds to organ divisions, manuals and stops. Other facilities such and couplers and presets are available. You may connect one or more MIDI keyboards to GENPO to provide the organ manuals, you can also assign one to be the 'pedalboard'.

GENPO is free, Open Source software.

The program was written as a result of the author trying some other 'virtual organs' and having a hard time either getting them installed, or using them. The philosophy behind the program is to combine a natural interface with full functionality. GENPO does not try hard to look exactly like an organ console - but an organist should feel instantly at home when presented with the console...


GENPO has been developed by Stephen Merrony in the UK, with the help of feedback from as far afield as Canada, Germany, Australia and Japan


  • Up to 8 divisions of up to 32 stops each
  • Up to 12 thumb pistons per division
  • Up to 16 toe pistons (whole organ combinations)
  • Cross-division coupling
  • Super- and sub-octave couplers
  • Thumb and toe pistons operable from MIDI keyboards/controllers
  • Support for MIDI swell pedals
  • Fully configurable keyboard shortcuts for stops
  • Built-in touchscreen support (if QT supports your touchscreen)
  • Up to 32 simultaneous stops pulled/channels of output

What do I need?

Minimum requirements are:

  • Linux - at least kernel 2.4
  • Qt Libraries - at least version 4 (KDE not required)
  • ALSA - at least version 0.9
  • (Kernel from 2.6 onwards include ALSA)
  • MIDI interface (supported by ALSA)
  • MIDI keyboard - the more the merrier
  • Some way of playing SoundFonts - either through a sound card which supports them or via on of several soft synths available such as FluidSynth or Timidity
  • An organ SoundFont (.SF2 file)

N.B. This site does not cover building or installing the ALSA libraries.


See the User Guide for full details, but here is a synopsis.

  1. Load a SoundFont (using sfxload or equivalent) or start your soft synth
  2. Start GENPO
  3. Load an organ definition in GENPO that corresponds the SoundFont you loaded
  4. 'Pull' some stops and start playing! Logo