Skip to content
Fork of jack-keyboard in order to port it to GTK+3
C CMake M4 Makefile
Branch: master
Clone or download
Pull request Compare This branch is 13 commits ahead, 1 commit behind draekko:master.
Fetching latest commit…
Cannot retrieve the latest commit at this time.
Type Name Latest commit message Commit time
Failed to load latest commit information.


Screenshot of jack-keyboard

What is it?

jack-keyboard is a virtual MIDI keyboard - a program that allows you to send JACK MIDI events (play ;-) using your PC keyboard. It's somewhat similar to vkeybd, except it uses JACK MIDI instead of ALSA, and the keyboard mapping is much better - it uses the same layout as trackers (like Impulse Tracker) did, so you have two and half octaves under your fingers.

How to compile it?

If you're using FreeBSD, install from ports - audio/jack-keyboard.

Otherwise, you need JACK with MIDI support, gtk+ 2.6 or higher, make(1), gcc and all the standard headers. Untar the file, type 'make install' and that's it. If there is any problem, drop me an email ( and I will help you. Really.

How to use it?

You need JACK with MIDI support and some softsynth that accepts JACK MIDI as input. Ghostess,, is a good choice. Of course you will also need some DSSI plugin that will make the actual sound. WhySynth is nice.

When you have all of these installed: first, run jackd. Then run ghostess with a plugin of choice. Then run jack-keyboard. Press 'z' key. You should hear sound.


Keyboard mapping is the same as in Impulse Tracker. This is your QWERTY keyboard:

   +----+----+    +----+----+----+    +----+----+
   | 2  | 3  |    | 5  | 6  | 7  |    | 9  | 0  |
| q  | w  | e  | r  | t  | y  | u  | i  | o  | p  |
       | s  | d  |    | g  | h  | j  |
    | z  | x  | c  | v  | b  | n  | m  |

And this is MIDI mapping.

   +----+----+    +----+----+----+    +----+----+
   |C#5 |D#5 |    |F#5 |G#5 |A#5 |    |C#6 |D#6 |
| C5 | D5 | E5 | F5 | G5 | A5 | B5 | C6 | D6 | E6 |
       |C#4 |D#4 |    |F#4 |G#4 |A#4 |
    | C4 | D4 | E4 | F4 | G4 | A4 | B4 |

Spacebar is a sustain key. Holding it when pressing or releasing key will make that key sustained, i.e. Note Off MIDI event won't be sent after releasing the key. To release (stop) all the sustained notes, press and release spacebar.

Holding Shift when pressing note will make it louder (it increases velocity). Holding Ctrl will do the opposite. You can change the default velocity by moving the Velocity slider. You can change the "high" and "low" velocity values by moving the slider while holding Shift or Ctrl keys.

Pressing "-" and "+" keys on numeric keypad changes the octave your keyboard is mapped to. Pressing "*" and "/" on numeric keypad changes MIDI program (instrument). Pressing Insert or Delete keys will connect jack-keyboard to the next/previous MIDI input port (it will cycle between running instances of ghostess, for example). Home and End keys change the MIDI channel. Page Up and Page Down keys switch the MIDI bank.

Esc works as a panic key - when you press it, all sound stops.

Setting channel/bank/program number directly

To switch directly to a channel, bank or program, enter its number on the numeric keypad (it won't be shown in any way) and press Home or End (to change channel), Page Up or Page Down (to change bank) or "/" or "*" (to change program). For example, to change to program number 123, type, on the numeric keypad, "123/", without quotes.


When -G xor -T is given, some informational messages in the title bar appear. They are supposed to be self explanatory. If you see "bank/program change not sent", it means that the bank/program numbers as seen in the title bar were not sent. In other words, synth the jack-keyboard is connected to may use different values. This happens at startup and after switching between synths (using Insert/Delete keys). To send bank/program change at startup, use -b and -p parame- ters. To automatically send bank/program change after reconnect, use the -u option.

Pianola mode

In addition to the MIDI output port, jack-keyboard also opens MIDI input (listening) port. MIDI events going into this port will be passed to the output port unmodified, except for channel number, which will be set to the one jack-keyboard is configured to use. Note On and Note Off MIDI events will cause visible effect (pressing and releasing) on keys, just like if they were being pressed using keyboard or mouse.

jack-keyboard will never connect to it's own MIDI input port. It will also refuse to connect to any other client whose name begins in "jack- keyboard", unless the "-k" option is given. It is, however, possible to connect these ports manually, using jack_connect or qjackctl; this may create feedback loop.


JACK Keyboard is distributed under the BSD license, two clause.


If you have any questions, comments, suggestions, patches or anything, let us know:

You can’t perform that action at this time.