[jestar_jokin]

A MIDI sequencer just outputs MIDI instructions, it doesn't generate sound unless it implements a synth (sound generator) of some sort.

You'd need to install something like loopMIDI, and direct the output of the sequencer to the input of a VST host, where you can load whatever synths you want.

[mpdehaan2]

to add to the above, on OS X, instead of loop MIDI, you can create a Virtual IAC bus instead. For someone with a Windows machine that has loopMIDI, if you want to send me a patch for Windows setup instructions, I'd love to add them.

I mostly develop on a Mac myself.

There are also some soft synths that don't need a VST host, some mentioned here - https://blog.landr.com/the-7-best-free-synth-vst-plugins/

I will admit I haven't used the setup.py having copied it from a previous project, and that's a stupid shortcut to make... I'll take a look at take care of the space issue.