Some notes:
- size() must be the first instruction of setup(). (I should gain one euro per time I wrote that! )
- You define original in setup() (giving a type), shadowing the one defined outside of setup(). The former one just disappear as soon as you exit setup(), so it isn't very useful. Just remove the String[] out of that line, and add those brackets to the outer one. It should take care of your issue.
- You might want to add a timer (check millis()) to avoid loading a text file 60 times per second, if you want decent performance.

I thought I had fixed the problem, but now it wont stop printing to the terminal. I'm not sure, but I think it may be skipping the "if" statement?

1. String originalFile;
   String currentFile;
   PFont font;
   
   
   void setup() {
     size(400,400);
     font = loadFont("CourierNew36.vlw");
     String[] original = loadStrings("nowplaying.txt");
     originalFile = original[0];
   }
   void draw() {
    
     String[] current = loadStrings("nowplaying.txt");
     currentFile = current[0];
     if (currentFile!=originalFile) {
       originalFile = currentFile;
       print(originalFile);
       textFont(font);
       text(originalFile,20,200);
       saveStrings("data\\original.txt",current);
     }
   }
   

Check the String reference.  To make String comparisons you must use the equals() method.

yeah, i got it now.  thanks for the help 

1. String originalFile;
   String currentFile;
   PFont font;
   
   
   void setup() {
     size(400,400);
     font = loadFont("CourierNew36.vlw");
     String[] original = loadStrings("nowplaying.txt");
     originalFile = original[0];
   }
   void draw() {
   
     String[] current = loadStrings("nowplaying.txt");
     currentFile = current[0];
     if(!currentFile.equals(originalFile))
    {
       originalFile = currentFile;
       print("Now Playing: " +originalFile+ "\n");
       textFont(font);
       text(originalFile,20,200);
       saveStrings("data\\original.txt",current);
   
   
     }
   }