I use Frescobaldi (an editor with integrated preview) to typeset music with LilyPond. It works different that rosegarden/musescore because you enter everything as text (like Tex) instead of clicking notes together in a GUI. I think it's faster in most cases if you know the note names (unless you want to write something unusual – then you have to check the manual).

I'm not entirely sure yet.

I might want to record myself playing with a microphone, prehaps even trying to create a virtual instrument out of it (not sure how that works, especially when some instruments (clarinet, which I play, comes to mind) can sound very different in different ranges of the instrument.

Also, I am seriously thinking about generating music algorithmically. Eventually, one idea would be to include algrithmically generated music in a video game, at which point the tricky thing is that the code would not have the whole machine to itself, and I wouldn't want to inflate said game's system requirements. (I've done a bit of this with generating random MIDI pitches.)

Again, I am unfamiliar with how things work in this field. If I decide I enjoy doing this, but the hardware isn't enough, I could then get a beefier machine, or perhaps I might set up my next main desktop for this sort of thing.

(Also, chances are I wouldn't use any guitar or vocals, and drums would likejy be used sparingly, if at all.)

Searching for that in the debian repository reveals another package I might look into, python3-ly.
(I have a strong background in computer programming, hence why Python libraries are of interest to me.)

That's a dependency of Frescobaldi and written by the same developers.

Cakewalk by Bandlab is free, but open source audacity is nice and there are alot of tutorials about it on youtube

That would explain why.

Of course, I think woreking with python3-ly directly could be useful if I want to algorithmically generale sheet music, or if I want to be able to transform it in various ways (like transposing it).