I am using the minim library for sound in an arcade music game I am making.  I have a switch to change states and go to different parts of the game, and each state has various sound needs.  For example, the default case in my switch contains code for displaying the game's title screen and looping a piece of music.

My problem is that when I test each state, the music or triggered sound samples play once but if I return to the same state later the sound will not play a second time.  I have been getting an error saying "Minim IOerror: stream closed" or something like that.  The error message does not come up every time but the sound always cuts out after I leave the state it was played in.

Thank you in advance for your help!

Thank you so much for responding, ddf.  I am definitely confused about when and where to close my audio objects, as well as what the difference is between object.close() and super.stop().  Here are the parts of my code having to do with sound and the state machine:


void setup()
{
 
 //multiple states using Minim
 Minim.start(this); //start Minim before doing anything with it
 
 //start menu setup
 theme = Minim.loadFile("wowiezowie.mp3",512); //store the mp3 in an AudioPlayer object
 
 //demo setup
 song = Minim.loadFile("joke.wav");
 
 
 //performance mode setup
 kick=Minim.loadSample("kick.wav",512);
 hat=Minim.loadSample("hat.wav",512);
 ride=Minim.loadSample("ride.wav",512);
 snare=Minim.loadSample("snare.wav",512);
 tom=Minim.loadSample("tom.wav",512);
/* tom2=Minim.loadSample("tomtest.wav",512);
 tom3=Minim.loadSample("tomtest2.wav",512);
 tom4=Minim.loadSample("tom4.wav",512);*/
}

void draw()
{
 background(0);
 if (keyPressed)
 {
   if(key=='1')
   {
     //state= "State_DEMO";
     test=1;
   }
   else if(key=='2')
   {
     //state= "State_PERFORM";
     test=2;
   }
   else if(key=='3')
   {
     //state="State_CHECK_INSTRUCT";
     test=3;
   }
   else if(key=='4')
   {
     //state="State_AUDIENCE";
     test=4;
   }
   else if(key=='5')
   {
     //state="State_CONTINUE";
     test=5;
   }
 }
 
 switch ( test )
 {
 //case "State_DEMO" :
   case 1:
   // Process for test = 1
      theme.close();
   
      song.play();
 
      beat.setSensitivity(300);  
      kickSize = snareSize = hatSize = 16;
   
   // taken from beat detect example
   beat.detect(song.mix);
   fill(255);
   if ( beat.isKick() ) kickSize = 32;
   if ( beat.isSnare() ) snareSize = 32;
   if ( beat.isHat() ) hatSize = 32;
   textSize(kickSize);
   text("KICK", width/4, height/2);
   textSize(snareSize);
   text("SNARE", width/2, height/2);
   textSize(hatSize);
   text("HAT", 3*width/4, height/2);
   kickSize = constrain(kickSize * 0.95, 16, 32);
   snareSize = constrain(snareSize * 0.95, 16, 32);
   hatSize = constrain(hatSize * 0.95, 16, 32);

   break;
   
 //case "State_PERFORM" :
   case 2:
        theme.close(); //stop the title song
        rhythms = loadStrings("rhythms.txt");
   
    if(keyPressed)
    {
      if(key=='k')
      {
          kick.trigger();
          delay(150);
      }
      if(key=='h')
      {
        hat.trigger();
        delay(150);
      }  
      if(key=='r')
      {
        ride.trigger();
        delay(150);
      }
      if(key=='s')
      {
        snare.trigger();
        delay(150);
      }
      if(key=='t')
      {
        tom.trigger();
        delay(150);
      }
      //if(key=='u')snare.trigger();
      //if(key=='i')tom2.trigger();
      //if(key=='o')tom2.trigger();  //don't need these last two really and they were crashing i think?
    }
   
   //   super.stop();  how to stop the sound within a state?
   
    break;

 //case "State_CHECK_INSTRUCT":
   case 3:
    text("in data check mode--not yet implemented", width/3,(height/4));
    text("developer transitions", width/3,(height/4)+200);
    break;
   
//  case "State_AUDIENCE" :
   case 4:
    text("in audience mode--not yet implemented", width/3,(height/4));
    text("developer transitions", width/3,(height/4)+200);
   break;  

//  case "State_CONTINUE" :
   case 5:
   // Process for test = 5
   text("Perform again? Press 1 for Yes, 6 for No", width/3,(height/4));
   if(keyPressed)
   {
     if(key=='1')
     {
       test=1;
     }
     else if (key=='6')
     {
       test=6;
     }
     else
     {
       test=5;
     }
   }
   break;

 default :
   // Process for all other cases is to go to the title state.
   background(0);
 
   image(title,(width/4)-130,height/4);
//if I load the sound file inside the state, the audio is distorted and I get an error message about java heap space in the thread.  do i need a new object every time i enter the state, and how do i do that correctly?  
// theme = Minim.loadFile("wowiezowie.mp3",512); //store the mp3 in an AudioPlayer object
   theme.loop();
   textFont(font,30);//declare font and font size
   text("Press 1 to start", width/3,(height/4)+200+a);
   a=(a+1);
   if(a>100)
   {
     a=0;
   }
   if(keyPressed)
   {
     if(key=='1')
     {
       test=1;
     }
     else test=6;
   }
   break;
 }

}


void stop()
{
 //from title state
 theme.close();
 super.stop();
 
 //from demo state
 song.close();
 
 //from performance state
 //always close Minim audio classes when you are done with them
 kick.close();
 hat.close();
 snare.close();
 tom.close();
 tom2.close();
 tom3.close();
 tom4.close();
 
 super.stop();
}

Oh wow, I totally forgot there was a pause() function.  I feel silly about that one.

Ok, so close() is for after I am completely done with a sound object and super.stop() is for when I am completely done with the library and everything because it tells Processing to close up the sketch?  I think I understand.

Thank you very much for taking the time to look at my messy code.  And thanks also for the State Patterns article.  I had been Googling "state machine" and never would have found that.