I changed python GUI into exe file by pyinstaller, and in that exe file, I cannot play back wav file sound

Question

I use python3.5, and I made a GUI with pyqt5. In that GUI, when I push the button, I can play back a music with wav file. This is the code.

import sys
from PyQt5 import QtCore, QtWidgets, QtMultimedia
from PyQt5.QtGui import QColor
from PyQt5.QtCore import *
from PyQt5.QtGui import *
from PyQt5.QtWidgets import *

class Window(QtWidgets.QWidget):
    def __init__(self):
        super(Window, self).__init__()
        self.setWindowTitle("sound")
        self.setGeometry(500,300,100,100)

        btn = QPushButton(self)
        btn.setIcon(self.style().standardIcon(getattr(QStyle,"SP_MediaPlay")))
        btn.setToolTip('音が出ます')
        btn.move(50, 25)  
        btn.clicked.connect(self.handlePlay)

        self.mediaPlayer = QtMultimedia.QMediaPlayer(self)
        sound=QtMultimedia.QMediaContent(QtCore.QUrl.fromLocalFile("Magia.wav"))
        self.mediaPlayer.setMedia(sound)

        self.show()


    def handlePlay(self):
        self.mediaPlayer.stop()
        self.mediaPlayer.play()


if __name__ == '__main__':

    app = QtWidgets.QApplication(sys.argv)
    window = Window()
    sys.exit(app.exec_())

By this code, you can make a GUI like this.

When you push the button, you can play back a music which is wav file. And I changed this python code into exe file by pyinstaller. But in the exe file, when I push the button, nothing happens. My OS environment is windows8.1 and 64bits.