Yeah, the screen is not updated throughout but just at the end of the function setup ().
You can move this into draw() :
file = new SoundFile(this,“PrincessZelda.mp3”);
file.play();
//Volume meter(0-1)
file.amp(.5);
And surround it with an if clause so it runs only once:
if(firstTime) {
…
firstTime=false;
}
Before setup you say
boolean firstTime=true;