Groove Music or Windows Media Player can't play WAV file written with scipy.io.wavfile.write

Question

I tried the code below to make a WAV file playing a fifth for 2 seconds:

C4 = 261.626
G4 = 391.995
t = np.arange(0, 2, 1/44100)
x = np.sin(2*np.pi*C4*t) + np.sin(