I finally received my music theory book this week. I bought Tonal Harmony, fourth edition, by Stefan Kostka and Dorothy Payne. Remember, I explained that my music theory knowledge is kind of like swiss cheese? I obviously know more than enough to play music properly, but I don't know some things that I consider basic knowledge. For instance, I can figure out scales on my own because I know if they sound right or not. I do not know the names of the scales, though, and am not familiar with a popular memory aid known as the circle of fifths. Know that I know the names of scales, though, I can relay to you that a piece that has four flats in the register is in fact A♭ major. Yay! I feel smarter already!
So, the only real notations of importance in Maple Leaf Rag are:
The tempo here is a march. This should not be played too quickly. Also note that the time is 2/4 time, where there are two beats to a measure and a quarter note gets one count (or beat). Four flats in the register means this part of the piece is in A♭ major.
This last bit of the piece is marked with a key change from A♭ major to D♭ major (see the extra flat?). I'm not sure what "Trio" means other than this is the third part of the piece and it is a bit different. I'm just guessing here, though. Anyone care to chime in?