Reddit mentions of The Norton Manual of Music Notation

Hey there, masters student in music composition here. Many, many kudos to you for throwing your stuff out there for all to see; I wish I could say I did the same at your stage in the game.

My undergraduate teacher would always harp on being absolutely meticulous with notation in our lessons. It is the first thing a conductor sees before a note is even played, and may mean the difference between your piece and another's getting performed. Plus, your music is your art and your craft, it should look as great as it sounds.

I would highly recommend you get your hands on Elaine Gould's Behind Bars, or maybe Heussenstamm's less intimidating Norton Manual of Music Notation to start with. These are just a few of the resources I've used thus far for everything relating to notation in music.

A few things I noticed are below, and I apologize if any of this is beyond MuseScore's capabilities:

1. Always start with some kind of tempo indication and dynamic level; this instantly gives the casual peruser something to latch on to, and sets the mood for the piece.
   
2. Make sure the division and grouping of beats is always clear. This is probably the most complicated to describe, but examples include beat 4 of m.5, RH, or beats 2/3 of m.14, LH. These could easily be misread by performers. I reference you to the above manuals or another musician who can explain it in person.
   
   
3. Accidentals, both "actual" and cautionary, as well as notation of pitches using the same written pitch class. Check out m.27, LH. It might be clearer to notate as "G-Bb-Cb-Bb-Cb", to avoid the confusion of the repeated "B". Avoid weird intervals like augmented seconds, diminished fourths, etc. A same-but-different scenario occurs between m.25-26, LH, where a G# and a G are written close to each other, but over the bar. The bar line cancels all accidentals, but the performer may not always realize it until it's too late.
   
   
4. Above all else, consider performance practice. For those that don't play the instruments they're writing for, this can be difficult. I recently wrote for guitar for the first time, and I spent hours trying to figure out if sonorities I wanted were congenial or even possible. For example, m.37, RH is impossible for any piano player, but can easily be restructured to have the lowest C in the left hand. A good player will do this naturally, but it's best to write it as exact as possible.
   
   I apologize that this is long-winded, music notation is complicated. But hopefully these tips get you started! Always think what you would want to see if given a completely new score to read, and write that.

I learned from Gardner Read. The Norton Manual of Music Notation is handy. It's old enough (30 years) that it has some material on manuscript preparation, but you can just skip that. What I currently have is Elaine Gould's Behind Bars, which I like but is probably overkill.

I'm not sure quite what you mean by "the emotional connotation side of music theory." If you're looking for e.g. what 17-18C musicians thought and wrote about the "doctrine of the affections", there are historical texts out there. But books that try to go deeper, i.e. to help you understand why a certain piece makes you feel a certain way, are doubtful, and I haven't found any of use in my own work.

I don't know of any sources on the history of modern notation, but the standard style guide I use is the Norton Manual of Music Notation by George Heussenstamm.