Music:
...
from rstem.sound import Sound, Note
from itertools import cycle
...
fire_sound = Sound("/home/pi/fire.wav")
hit_sound = Sound("/home/pi/hit.wav")
notes = cycle([Note('B3'), Note('G3'), Note('E3'), Note('C3')])
...
while True:
...
# Button was pressed - launch missile
...
fire_sound.play()
...
# Move alien
if ...:
next(notes).play(duration=0.20)
...
# Check for collision
if ...:
...
hit_sound.play()
Full project: