Ardour is free and open source.

You might also want to try LMMS. Pair it up with ZynAddSubFX as the synth and you have a pretty competent studio.

Relevant submission: https://midination.com/free-music-production-software/

Less ambiguous (in English) to use a loan-word and say "Ardour is libre and open source".

I would argue that it's not only ambiguous but harmful to use the word "free" to describe libre software at this point.

So many people have "Free means it steals your data" beaten into their heads at this point.

This is of course referring to the general population. I would assume that people on HN have no issues with Libre-Free vs Beer-Free.

LV2 plugins aren't supported in Reaper but are in Ardour, this makes quite a difference in Linux. In my opinion the anywhere to anywhere routing is better in Ardour. That said, I moved from Ardour to Reaper and prefer Reaper.

I believe Ardour has an open license and Reaper has a proprietary licence. In terms of functionality and ease of use however, I think Reaper is hard to beat.