dtgreene: Any thoughts on them?
Vythonaut: Since you've already received your answers about the applications in question, let me ask you if you're playing a *real* musical instrument; if you plan to connect an instrument/microphone, do you already have an audio interface? If not, you should consider getting one, unless all your music will be written through midi controllers/VST instruments etc. and monitoring will be done using normal desktop pc speakers or headphones.
Also, i'm not sure if your specs will cut it for the music you're going to produce, but audio recording/editing that spans over many channels is quite the task for a PC to handle and you may find that you need more RAM or a faster CPU, although if you're only going for a guitar/vocals plus some midi (let's say some piano and/or drums), you'll be fine.
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.)
mk47at: 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).
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.)