I'm not sure if this is even the right forum for this question, but whatever.
So, I went to start writing a concert band piece, but before I started that, I wanted to do a reduced score version of it first, to get my ideas down on paper. So, I made a score with a regular 2-stave piano, and then I added two more staves onto that, to give me 4 lines. (Which I thought was a good amount to be able to condense an entire concert band onto.) The problem I didn't foresee is that all 4 staves are still being treated as one instrument, and that can come with it's own annoyances. For instance, any dynamic that I apply to any stave is instantly applied to all 4.
So, while I'd imagine this is unlikely, is there any way that I can take this one "instrument" and split it up so that each stave is its own separate instrument? Obviously, I could just start from scratch and make 4 independent lines from the start, but I really don't want to have to restart or lose any of my progress. I'm looking to see if there's a way to take these existing staves and make them their own instruments without altering the piece in any other way.
Thanks! If there's any other questions you have, please let me know.
Press' I' and add the instruments, not connected staves.
Open the Inspector (F8) click on a dynamic and add its properties.
See also: https://musescore.org/en/handbook/copy-and-paste
If the main concern is the dynamics, you can use the inspector and apply it to the Staff only as Shoichi suggested.
If you mean that you want to keep this as only four staves, but you want those four staves to be separate instruments instead of one, just add the new instruments via Edit / Instruments and copy / paste the existing contents to them normally.
If you mean that each staff currently has chords of several notes - like a single trumpet staff with three-note chords, one note each for 1st, 2nd, and 3rd trumpet - then see Edit / Tools / Explode. This will separate the chords into individual parts on the staves below (so first add the empty staves for the other trumpet parts).
If you mean something else, please attach your score and describe what you are trying to do in more detail.