Here is a viideo of Black Sabbath played on Fedora 32
I used Guitarix to process the guitar sound in real time. The latency with jackaudio is around 10ms.
The backing tracks are played using TuxGuitar 1.5.4 with the 63mg The Xioad Bank soundfont.
Everything is managed via Ray Session 0.9.2 manager and the sound is adjusted using non mixer 1.2.0.
The webcam has been recorded using XawTV 3.107.
The whole video is recorded using simplescreenrecorder 0.4.2.
Fedora 32 has been used with some package from this personnal repo have been used:
The last RT kernel is used: 5.10.17-rt32
I feel the sound is not that bad at all. Open source tools rules !