Helm is a free, cross-platform, polyphonic synthesizer with a flexible modulation system. Helm is open source and you are free to run it anywhere, study and change the source code, and redistribute exact or modified copies of Helm.
Sorry for the spelling and phonetic errors in the text.
Owner and main writer of MintGuide.org is not a native English speaker.
Is Helm really free?
Helm is free as in freedom. This means you control this software, it doesn't control you.
In terms of money, Helm is pay what you want. So you are free to pay nothing.
Where does Helm store files?
Standalone - /usr/bin/helm
LV2 - /usr/lib/lv2/helm.lv2
VST - /usr/lib/lxvst/helm.so (if installed)
Local Presets - ~/.helm/patches
Factory Files - /usr/share/helm/
Config File - ~/.helm/Helm.config
Installation latest version into Linux Mint: