There's a free, simple synthesizer that's available for Linux as a VST plugin. Runs in Ardour, Carla. Simple one OSC, one sub-OSC construction, with an arppegiator which syncs automatically to jack transport. http://uhedownloads.heckmannaudiogmb.netdna-cdn.com/penguin/release/3965/Po… Info and user guide: https://www.u-he.com/cms/podolski