For writing music sheets, I use LilyPond.

I like it quite a lot, been using it for years. It think it gives the best looking output.

LMMS is a fairly intuitive editor that makes it easy to build midi tracks and drum loops. Can't really record tho.

Famistudio is specific to chiptune music. I think it's a tracker. Along the same lines, there's MilkyTracker. I haven't figured out how to use them, but they're neat.

I use a number of things on this github repo of FOSS audio tools.

Things I can recommend:
Vital (wavetable synth)
Dexed (clone of Yamaha DX7, uses sysex preset ibraries)
Dragonfly Reverb (great free reverbs)

Things I need to check out more:
VCV Rack (modular synths)
Neural Amp Modeler (guitar impulse loader)

Bespoke Synth is pretty cool.

Lots of cool classic synth emulators here - true emulators, you need to ahem dump the firmware files from your legally owned gear.

Relevant to programming because they are emulating the DSP chips and they apparently figured them out via de-lidding techniques etc

https://theusualsuspects.io/

there are whole distros with audio focus: ubuntu studio & fedora jam and probably others.

maybe check what they come packaged with. not sure if it's all open source though.

Maybe this post would be better suited for !musicproduction@sh.itjust.works ?

I used Ardour, an entire open source DAW. Definitely more powerful than Audacity for this kind of thing, and I'm much more comfortable with MIDI notation than traditional music notation, too. I did eventually switch to Bitwig though, because I use a lot of samples and synth plugins and Bitwig's workflow and UI for that is just a lot better than Ardour's.

There are quite a few pretty good open source VST/LV2 plugins, e.g. ZynAddSubFX is a really powerful software synth and Dragonfly Reverb is a neat reverb. There are more, unfortunately many open source plugins are only available in LV2 format and unfortunately Bitwig doesn't support LV2.

I’d recommend the fork Tenacity over Audacity since the latter has been hijacked by Muse Group.

Not really in use due to time constraints but i have installed pro-audio, which is a nice collection of linux compatible audio software:

https://archlinux.org/groups/x86_64/pro-audio/