FSR + Music Maker Shield struggle

Hello guys

I’m trying to use 2 FSR’s to trigger for each sensor a specific soundfile. Unfortunately it freezes sometimes (crash = no sound) and if you stopp pressing the FSR it should stop playing the music.

How can I do this? I tried to fix this problem for 3h and now i need your help.
Thank’s in advance!

#include <SPI.h>
#include <Adafruit_VS1053.h>
#include <SD.h>

// These are the pins used for the breakout example
#define BREAKOUT_RESET  9      // VS1053 reset pin (output)
#define BREAKOUT_CS     10     // VS1053 chip select pin (output)
#define BREAKOUT_DCS    8      // VS1053 Data/command select pin (output)

// These are the pins used for the music maker shield
#define SHIELD_RESET  -1      // VS1053 reset pin (unused!)
#define SHIELD_CS     7      // VS1053 chip select pin (output)
#define SHIELD_DCS    6      // VS1053 Data/command select pin (output)

// These are common pins between breakout and shield
#define CARDCS 4     // Card chip select pin

// DREQ should be an Int pin, see http://arduino.cc/en/Reference/attachInterrupt
#define DREQ 3       // VS1053 Data request, ideally an Interrupt pin

Adafruit_VS1053_FilePlayer musicPlayer =
  // create breakout-example object!
  //Adafruit_VS1053_FilePlayer(BREAKOUT_RESET, BREAKOUT_CS, BREAKOUT_DCS, DREQ, CARDCS);
  // create shield-example object!
  Adafruit_VS1053_FilePlayer(SHIELD_RESET, SHIELD_CS, SHIELD_DCS, DREQ, CARDCS);


int lastSensorState = LOW;   // sensor's previous state
int lastSensorState1 = LOW;
int threshold = 300;   // an arbitrary threshold value

void setup() {
  Serial.begin(9600);
  Serial.println("Adafruit VS1053 Simple Test");

  if (! musicPlayer.begin()) { // initialise the music player
    Serial.println(F("Couldn't find VS1053, do you have the right pins defined?"));
    while (1);
  }
  Serial.println(F("VS1053 found"));

  if (!SD.begin(CARDCS)) {
    Serial.println(F("SD failed, or not present"));
    while (1);  // don't do anything more
  }

  // list files
  printDirectory(SD.open("/"), 0);

  // Set volume for left, right channels. lower numbers == louder volume!
  musicPlayer.setVolume(20, 20);

  // Timer interrupts are not suggested, better to use DREQ interrupt!
  //musicPlayer.useInterrupt(VS1053_FILEPLAYER_TIMER0_INT); // timer int

  // If DREQ is on an interrupt pin (on uno, #2 or #3) we can do background
  // audio playing
  musicPlayer.useInterrupt(VS1053_FILEPLAYER_PIN_INT);  // DREQ int
  if (! musicPlayer.useInterrupt(VS1053_FILEPLAYER_PIN_INT)) {
    Serial.println(F("DREQ pin is not an interrupt pin"));
  }
}

void loop() {

  // read the sensor:
  int sensorState = analogRead(A0);
  int sensorState1 = analogRead(A1);

  // if it's above the threshold:
  if (sensorState >= threshold) {
    // check that the previous value was below the threshold:
    if (lastSensorState < threshold) {
      musicPlayer.startPlayingFile("track001.mp3");
      Serial.println(F("Playing track001"));
      Serial.println("Sensor crossed the threshold");
    }
  }

  // if it's above the threshold:
  if (sensorState1 >= threshold) {
    // check that the previous value was below the threshold:
    if (lastSensorState1 < threshold) {
      musicPlayer.startPlayingFile("track002.mp3");
      Serial.println(F("Playing track002"));
      Serial.println("Sensor crossed the threshold");
    }
  }

  // save button state for next comparison:
  lastSensorState = sensorState;
  lastSensorState1 = sensorState1;

  if (Serial.available()) {
    char c = Serial.read();

    // if we get an 's' on the serial console, stop!
    if (c == 's') {
      musicPlayer.stopPlaying();
    }

    // if we get an 'p' on the serial console, pause/unpause!
    if (c == 'p') {
      if (! musicPlayer.paused()) {
        Serial.println("Paused");
        musicPlayer.pausePlaying(true);
      } else {
        Serial.println("Resumed");
        musicPlayer.pausePlaying(false);
      }
    }
  }

  delay(100);
}


/// File listing helper
void printDirectory(File dir, int numTabs) {
  while (true) {

    File entry =  dir.openNextFile();
    if (! entry) {
      // no more files
      //Serial.println("**nomorefiles**");
      break;
    }
    for (uint8_t i = 0; i < numTabs; i++) {
      Serial.print('\t');
    }
    Serial.print(entry.name());
    if (entry.isDirectory()) {
      Serial.println("/");
      printDirectory(entry, numTabs + 1);
    } else {
      // files have sizes, directories do not
      Serial.print("\t\t");
      Serial.println(entry.size(), DEC);
    }
    entry.close();
  }
}