JJazzLab 3.0 BETA version


NOTE: This is a pre-release, please help by reporting bugs as explained here.


Windows 32-bit version: JJazzLab-3.0.beta1-Win32-Setup.exe

Windows 64-bit version: JJazzLab-3.0.beta1-Win64-Setup.exe

Linux x64: JJazzLab-3.0.beta1-Linux.zip

Mac OSX: JJazzLab-3.0.beta1-Mac.zip

JJazzLab 3.0 New features

Dark Theme with improved graphics

Light Theme is gone, it was too much work to maintain 2 themes.

Auto-update of the playing backing track

When a backing track is playing, changing chord symbols or rhythm parameters (e.g. change variation, add a drums fill, etc.) will immediatly update the backing track (no more need to press Stop then Play again). You can turn this off via the toggle button shown below.

Auto-update button image

Improved rhythm selection dialog

You can now preview the different variations of a rhythm, permanently delete a rhythm file, or open the directory of a rhythm in a file explorer.

New Drums Transform rhythm parameter

For example make the toms louder in the intro song part, or transform the closed hi-hat into an open hi-hat in the chorus song parts.

New Custom Phrase rhythm parameter

For example use your own bass line for the chorus song part. To add notes to your custom phrase, drag & drop a Midi file or open an external Midi editor from JJazzLab (you can configure one in the General panel of the Options, for Windows I recommend MidiEditor, a lightweight and free software).

Copy/Paste rhythm parameter values

For example apply your custom percussion phrase to other song parts.

Copy paste rp value image

Jump to previous/next song part

Use F1/F2 from the keyboard. These commands can also be used remotely via Midi, see “Midi input and Midi remote commands” below.

Previous/Next song part commands image

Notes viewer

View notes of the selected chord symbol, or from a playing track.

Notes viewer guitar Notes viewer piano

Improvisation help

JJazzLab generates guidelines in your chord leadsheet for selected improvisation exercises. JJazzLab 3.0 proposes 3 exercises from the great book “How To Improvise” by Hal Crook. Others will be added in future versions (your inputs are welcome!).

Midi input and remote Midi commands

You can trigger music control actions (play, stop, …) from any Midi input sequence via Midi Learn.

(Pseudo) arranger keyboard mode

Select a song part, press the Arranger Play button and JJazzLab will recognize the chords received on Midi input and update the backing track accordingly.

IMPORTANT: This is NOT a true realtime arranger mode, it’s more for educational purpose.

User tracks

Add a user track to your backing track. To add notes to the user track drag & drop a Midi file to the user rectangle area, or open an external Midi editor from JJazzLab (you can configure one in the General panel of the Options, for Windows I recommend MidiEditor, a lightweight and free software).

IMPORTANT: JJazzLab does not support Midi input recording.

Export Midi files via drag & drop from the Mix Console

You can easily export the whole backing track or just one instrument track using drag & drop from the Mix Console. This is convenient when working with a DAW (Cubase, Reaper, etc.) with JJazzLab.

Export via drag drop image

Adjust audio latency

Sometimes audio notes (the notes you hear) lag a bit behind the user interface changes. This depends on your hardware configuration. You can now fix this by adjusting the audio latency from the Output Synth Editor.


  • New keyboard shortcut Shift-SPACE to stop a song (SPACE is play/pause)
  • New popup menu action “Insert section” in the chord leadsheet editor
  • API design improvements
  • Improved JavaDocs
  • Bug fixes


Visit the JJazzLab-X page on GitHub for more details about the implemented Issues.


[enhancement] Use latest JDK AdoptOpenJDK 11.0.13 #229
[enhancement] Move half/double chord leadsheet + duplicate song actions to Edit menu #226
[enhancement] Add a way to show improvisation hints on the leadsheet #224
[enhancement] Transform rhythm phrases, e.g. change hi-hat to ride on a given song part #222
[enhancement] Export to Midi using mouse dragging from the Mix Console #221
[enhancement] Add user tracks for e.g. melody/impro track(s) #219
[enhancement] Add Midi learn capability for Midi remote commands #215
[enhancement] Add possibility to customize instrument phrases on each song part #214
[enhancement] Improve design of icons open/save/undo/redo/play etc. #212
[enhancement] If song is changed while playing, automatically update the sequence when possible #211
[enhancement] Add "Insert Section" action in the Chord LeadSheet popup menu #210
[enhancement] Remove Check for update menu #209
[enhancement] Pseudo arranger keyboard: enter chords via Midi to control JJazzLab playback (not pure realtime) #208
[enhancement] Add a rhythm parameter to alter the velocity of individual drums instruments (eg "make hi-hat louder") #207
[enhancement] Add possibility to show selected chord symbol as guitar chord diagrams or piano chords #206
[enhancement] Add possibility to preview the different variations of a rhythm #205
[enhancement] Delete style files from JJazzLab or explore rhythm folder of a specified rhythm #204
[enhancement] Add copy/paste rhythm parameter value across song parts #197
[enhancement] Enable RhythmParameter, ie with non enumerable values #196
[enhancement] Improve design of mix console channels, knobs + slider #195
[enhancement] Add commands to make playback jump to the next song part (or previous one) #193
[enhancement] Add a way to take into account output synth audio latency #192
[enhancement] Add way to compensate for the output synth audio latency #191
[enhancement] Add piano keyboard to show backing track notes in real time #190
[enhancement] Upgrade to AdoptOpenJDK 11.0.10-9 #187
[enhancement] Add shortcut to stop and reset playback (shift-space) #184
[enhancement] Remove the non-API/SPI classes from the online javadoc #176
[enhancement][help wanted] Add customizable Midi input remote commands (play/pause, stop, next song part, previous song part) #161

Bug Fixes:

[bug] Playing bar in chordleadsheet editor sometimes hidden on first row (incorrect scroll) #227
[bug] Build sequence exception when several song parts use an adapted rhythm #220
[bug] Song mix file is ignored when the song contains an adapted rhythm #218
[bug] Play selection on a chord leadsheet does not take into account the selected song part #189
[bug][high priority] In-place editors don't work with Dark Theme (mix console, song part name, ...) #188
[bug] NullPointerException in some cases when changing RhythmProvider in Rhythm selection dialog #186