import pygame
from mutagen.mp3 import MP3

SONG_END = pygame.USEREVENT + 1

pygame.display.set_caption('MP3 with Pygame')
pygame.display.set_mode((150, 50), pygame.RESIZABLE)

mp3filename = '/home/mihai/Music/ZAZ/Zaz-Je-Suis-Un-Homme_(get-tune.net).mp3'
audio = MP3(mp3filename)
audio_len = audio.info.length

pygame.mixer.init()
pygame.mixer.music.load(mp3filename)
pygame.mixer.music.set_endevent(SONG_END)

pygame.mixer.music.play(-1)

done = False

while not done:
 for event in pygame.event.get():
        if event.type == pygame.QUIT:
            done = True
            pygame.mixer.quit()
        if event.type ==  SONG_END:
            done = True
        if event.type == pygame.KEYDOWN and event.key == pygame.K_SPACE:
            pygame.mixer.music.rewind()
            pygame.mixer.music.set_pos(audio_len//2) # does not work, and freezes the program. need to use kill -9 ... !a