It's not short, but I was introduced to the concept in a video series on FLOSS Linux audio tools: https://www.youtube.com/watch?v=hdPPPeq82hw&list=PLf_MTToSAxRITjUHgpIPUQTZdGvNQR-0p&index=1 Specifically, you can play with it yourself with a tool like ZynAddSubFX's (https://zynaddsubfx.sourceforge.io/) virtual keyboard, where you can enable microtonal under scale settings and tweak to whatever tuning you want (see... - Source: Hacker News / 4 days ago

I've also used ZynAddSubFX, which is also a very powerful synth, though its interface (at least to me) is a bit of a clusterfuck. You could also try browsing this index of microtonally capable synths on the xenharmonic wiki. Source: about 1 year ago

The code for this can be found here on shadertoy! The audio was made with an Ibanez bass, Guitarix, Hydrogen Drums, ZynaddSubFX and Ardour! Source: over 2 years ago

Here is an additive synth - https://zynaddsubfx.sourceforge.io/. Source: over 2 years ago

There are VSTs for Linux. Surge, Vital, and ZynAddSubFx are three prominent examples, as well as OxeFM, Dexed, and plenty I'm forgetting. Surge and Zyn also come LV2 and DSSI, which are native Linux formats. For those who don't know, the VST3 SDK supports Linux, and is released under GPLv3 by Steinberg. Source: almost 3 years ago

So what’s the difference between this and Ultrastar Deluxe? https://usdx.eu/. Source: over 1 year ago

UltraStar Deluxe is a good and free SingStar clone. You have to provide your own songs, though. Source: over 2 years ago

Https://usdx.eu/ - works, rather old, abandoned. Source: almost 3 years ago

Well, you have https://www.karaoke-forever.com/, which you could probably host and get setup or, if it's not as important for you to have it self-hosted to access everywhere but just "self-hosted" on a local machine, you have https://usdx.eu/, which I believe is the closest to what you will find of Singstar. Source: almost 3 years ago