I've just noticed, Cthulhu (

) and realized that there ARE VST plugins that can generate MIDI data (eg. loop sequencers, arpegiators) which can be sent to other tracks within a DAW like Ableton or FL Studio.

I want to write one of these myself, to algorithmically generate musical tracks that are sent to other instruments within my DAW. But I can't find any tutorials or examples of how to do this.

All the VST tutorials and examples I'm seeing seem to be of VSTs as instruments or effects.

Can anyone give me some pointers to where I can find out more about programming a VST that sends MIDI?


While Cthulhu is great for comming up with new and creative patterns, you could very well just us the in-build chord tracks in Cubase (or the similar chorder in Studio One) for simple harmonies and circle of fifths stuff.

It's acctualy a time saver when working with fixed harmonies music - like those in folk or indie genres.

Tutorial video on this chord feature:


One interesting possibility I've discovered is ReaJS which is a free VST plugin from Cockos that you can get as part of the free ReaPlugs VST suite : https://www.reaper.fm/reaplugs/

You seem to write scripts for the plugin in something called "js" (that doesn't seem anything to do with Javascript).

There's a manual here : https://www.reaper.fm/sdk/js/js.php


I had some success writing a MIDI-generating VST plugin using the JUCE framework. Besides audio and MIDI support for standalones and VST & AU plugins, it also gives you a pretty good UI framework and the tutorials seem thorough.

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