I moved forward and soldered my board today. Prior to doing so, I decided to record a demonstration of my synthesizer in use, in case there would be errors during the soldering process. Sure enough, it turned out my decision was the right call to make, as after I soldered all of the components onto my proto-perfboard, the LCD screen stopped outputting text.
I tried looking at the pins underneath the board, and soldered a bit more to make sure the pins were correctly connected. Initially, the issue was that the pins were not properly soldered onto the board, and therefore did not light up the LED backlight for the LCD screen. After that I managed to get everything up-and-running, but for some reason the text for the menus and items would no longer be displayed. I will try soldering a bit more tomorrow, to see if I may possibly fix it.
Fortunately, the synthesizer itself still works so I will still be able to demonstrate a working, audible product in the class.