Why is my partially transparent image blitted fully opaque?

Question

I have a part in my program that should display the currently playing song's name for the first 4 seconds, then fade out. Even though Surface.get_alpha() returns expected results, the image still does not fade out.

Why is this? How can I make it work?

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My code looks like this:

for event in settings.events:
    if pygame.mixer.music.get_pos() < 4000 and sounds.music.volume != 0:
        #This part creates the surface and determines the position 
        show = 40 * 4
        font = pygame.font.SysFont(typeface, 15)
        songname = font.render(sounds.music.playlist[0], True, settings.color)
        font_pos = songname.get_rect()
        font_pos.right = screenx - 10
        font_pos.top = 10
        alpha = 255
    if event.type == USEREVENT + 1 and sounds.music.volume != 0:
        #The userevent is there to ensure it will fade out with the same speed
        #and not being related to fps
        #this decreases alpha
        show -= 1 if show > 0 else False
        if show < 40 * 4 and alpha > 0:
            alpha -= 1.6
        songname.set_alpha(int(alpha))

if pygame.mixer.music.get_volume() != 0.0 and show != 0:
    #This does actually return the correct results
    print songname.get_alpha(), alpha
    screen.blit(songname, font_pos)