What is JJazzLab


JJazzLab is a Midi-based application which automatically generates backing tracks (a musical accompaniment) for any song. It’s a jam buddy to have fun improvising, learn new stuff or just practice your instrument. It’s also a great tool for teachers.



(don’t want to read ? try the video tutorials !)

What makes JJazzLab different

More dynamics and variations

JJazzlab rhythms can support many intensity and complexity variations. You can start a solo slowly and gradually build up the atmosphere, like with a real band.

Rhythmic accents

Use chord anticipations and rhythmic accents to underline the melody or spice up your arrangement.

Yamaha style files + YamJJazz extension files

JJazzLab can read most of the style files used by the Yamaha arranger keyboards (PSR family, Tyros 1 and 2). Benefit from hundreds of ready-to-use Yamaha styles available for free on the web.

JJazzLab also introduces YamJJazz extension files to add even more variations to a standard Yamaha style.

Built on an open-source modular platform

JJazzLab is built upon JJazzLab-X, the open-source platform dedicated to backing tracks generation. The modularity and openness of the platform makes it easy for developers to add new features or new rhythm generation engines.

How it works

JJazzLab image
Use the Chord LeadSheet Editor to:

  • Add chord symbols, eg “Cm6”, “Ab7”
  • Add sections, eg “A”, “B”, “verse”, “chorus”, …
  • Move and edit chords to adjust rhythm accents, interpretation or harmony

Use the Song Structure Editor to:

  • Define the order of sections, eg “AABA”, “verse verse chorus verse”, …
  • Select rhythm(s) to be used
  • Adjust the rhythm parameters to introduce dynamics, eg variation, intensity, fill, muted instrument, …

Use the mix console to adjust the mix of each rhythm instrument:

  • Select the instrument to be used on your sound device
  • Adjust volume, panoramic, reverb, chorus
  • Mute, solo, transpose