mediaplayer waveshield sound stutters

hey I’ve tried to get a magnetic sensor and wave shield to play some music while you crank a handle and then pause when you stop turning, I got it to play when you turn and pause when you stop, but it stutters in the sound around. every 1 to 3 sec. is there anyone who has a good explanation on it and possibly a solution.
My goal is that when you begin turning the handle it starts to play, and when it stops then breaks the sound

the code I use is built on mediaplayer Class

#include <avr/pgmspace.h>
#include "util.h"
#include "MediaPlayer.h"

int onboardLed = 8; // digital
int frontLed = 9; // digital
MediaPlayer mediaPlayer; // create only one object, must be global

void loop()                    
  int analogValue = analogRead(0);
  int Button;
 if (analogValue <= 50){
  digitalWrite (onboardLed, HIGH);
  Button = HIGH;
  digitalWrite (onboardLed, LOW);
  Button = LOW;
 if (Button == HIGH){
 if (Button == HIGH && ! mediaPlayer.isPlaying()) {"DERWISCH.WAV");