Frequently Asked Questions

I like JJazzLab, how can I help?

  • Donate to keep JJazzLab 100% free, without any ad

  • Help translate JJazzLab (especially if you speak japanese and korean)

  • Contribute to improve this documentation

  • Like the videos and subscribe the YouTube channel

  • Record a video of yourself playing along with JJazzLab: videos will be put on the JJazzLab YouTube channel

  • Spread the word ! Talk and add links to www.jjazzlab.org on social networks, blogs, websites, etc.

  • If you're a developer, contribute code on GitHub.

I use MacOS, I can't find menu Tools/Options?

On MacOS the Options are accessed via the main menu JJazzLab/Preferences.

How do I transpose a song?

  1. Select all the chord symbols (right-click menu Select all the chord symbols)

  2. Use the mouse-wheel, or right-click menu Transpose

Can I use VST/AU plugins with JJazzLab?

Yes, but not directly because JJazzLab can not host VST plugins.

  1. Install a virtual midi device and a VST Host software on your computer. You'll find on the web free applications for Windows, Linux and Mac. For example use loopMIDI (we recommend to disable its feedback detection in the Advanced settings) and SoundBridge on Windows.

  2. In JJazzLab, go to Midi options and set the Midi out device to loopMIDI

  3. In your VST Host software, set the Midi in device to loopMidi and make sure the VST Host and the VST plugins are configured so that all Midi channels (1-16) are received.

  4. Play a song in JJazzLab: you should hear the VST instruments

  5. If you don't want to select the VST sounds directly from JJazzLab, you might want to Disable all Midi parameters from the Midi menu in the Mix Console.

How to generate an audio file (.mp3, .wav, etc.) from a JJazzLab backing track?

From JJazzLab 4, just use menu File/Export to audio. If you select the option "Separate tracks", one audio file will be generated per track.

How to force a clean re-installation?

You need to reset all JJazzLab user settings (uninstall/re-install is not enough).

The simple way: menu Tools/Options/Advanced, button Reset all user settings.

The hard way: find the location of your Netbeans user dir in menu Help/About/System Information, **exit JJazzLab, then delete the Netbeans user dir**.

I don't have administration privileges on my Windows computer, can I install JJazzLab?

Yes. When first prompted by the JJazzLab installer, select "Install only for me", then select an installation directory where you have write access (in My Documents for example).

How to get better sounds?

From JJazzLab 4, the application embeds a ready-to-use software synth (FluidSynth) optimally configured for JJazzLab, with decent sounds.

To get even better sounds, you'll need to use a hardware synth or VST/AU plugins.

There is a free version of Halion Sonic SE from Steinberg which can be used with JJazzLab to get really good sounding backing tracks, more info on the JJazzLab forum.

I have a Yamaha arranger keyboard (Tyros, PSR, ...), how can I use it with JJazzLab?

JJazzLab can drive your keyboard to benefit from its optimized sounds.

  • Connect your keyboard via Midi

  • Go to the Midi Out tab of Options/Preferences

  • Select the Midi output connected to your synth

  • In the Output Synth part, select Add synth from file..., and choose YamahaRefSynth.ins.

How to make fonts bigger?

In the JJazzLab installation directory, edit the file etc/jjazzlab.conf and add --fontsize 16 (16 or any other value, default is 11) in the default_options variable, you should end up with something like this:

default_options="--branding jjazzlab -J-Djjazzlab.version=2.2.0 -J-Dplugin.manager.check.new.plugins=true -J-Dplugin.manager.check.interval=EVERY_DAY --fontsize 16"

Restart JJazzLab. All menus should look bigger now.

This won't solve everything though, as some editor fonts do not depend on this setting. But you can tweak some of them using menu Tools/Options/Theme. Check each item in the list and if there is a font defined, change it to make it bigger. The user settings are automatically saved, so you need to do this only once.

If you use 4K or 5K monitors, JJazzLab may look too small, with unreadable fonts. In this case add -J-Dsun.java2d.uiScale=2 in the default_options variable, like in the example above. JJazzLab will look twice as bigger.

Can I start JJazzLab with command line arguments?

You can pass one or more .sng file names on the command line, JJazzLab will open them upon start.

# Example on Win10 (x64)
"C:\Program Files\JJazzLab\bin\jjazzlab64.exe" "C:\my dir\MySong.sng" "D:\AnotherSong.sng"

How to submit a bug? How to find the "log" file?

Create a new thread in the JJazzLab forum or, if you're a GitHub user, create an issue.

We need the following information in order to help you:

  • Provide the content of the log file

  • Describe what does not work as expected

  • Describe the sequence of actions that caused the issue

A new log file is created upon each start of JJazzLab. It's important to get the right log file when the problem occured.

To get the log file content:

  1. After the problem has occured, go to menu Tools/Options/Advanced

  2. Click on Show Log Window

  3. Copy & paste the full content of this window in your bug report

If for some reason the above does not work:

  1. Go to menu Help/About and find the location of your Netbeans user dir. For ex. on Windows C:\Users\MyName\AppData\Roaming\jjazzlab\2.2 For ex. on Linux /home/MyName/.jjazzlab/2.2

  2. Open an explorer, go to this directory then to the var/log subdirectory

  3. The last log file is messages.log, the previous one is messages.log.1, the before previous is messages.log.2, etc.

  4. Find the relevant log file and send it with your bug report

If you can't find the Netbeans user dir., make sure your explorer shows the hidden files (e.g. the AppData directory is usually hidden on Windows)

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