pygame: store and load different background music

have a game with one main screen and one pause screen. I want there to be a different music to played for each screen from where they left off previously. The following is the relevant section of my code:

while running:

    if Options.want_pause:
        if load_count == 0 and Options.want_Music: # clicking the button to swap screens resets load_count to 0
            mpos = pygame.mixer.music.get_pos()  # gets pos of music from main mainwindow
            music = pygame.mixer.music.load('Pause music.mp3')
            pygame.mixer.music.set_pos(ppos/1000) # plays from previous music position
            pygame.mixer.music.play(-1)
            load_count = 1

        pausewindow(win_width, win_height, width, height)
    else:
        if load_count == 0 and Options.want_Music:
            ppos = pygame.mixer.music.get_pos()
            music = pygame.mixer.music.load('Main music.mp3')
            try: #starts from beginning the first time, after which mpos will be definied
                pygame.mixer.music.set_pos(mpos/1000)
            except NameError:
                pygame.mixer.music.play(-1)
            pygame.mixer.music.play(-1)
            load_count = 1
        set_dirs(cur_block, width, height)
        gamewindow(win_width, win_height, width, height, no)
    #etc

it works fine if I don't want to resume the music and just start all over from the beginning, (i.e. if I get rid of the get_pos and set_pos lines), but the above gives me the following error:

Traceback (most recent call last): File "C:/Vijay Stuff/Coding stuff/pycharm projects/Summer projects 2020/Tetris/Tetris 1.5.2.py", line 462, in pygame.mixer.music.set_pos(mpos/1000) pygame.error: set_pos unsupported for this codec

I also tried using pygame.mixer.music.play(-1, mpos/1000) (and same for the other one) and although this doesn't give an error, it doesn't work properly. Basically it only works if I enter the exit the other screen very quickly, which is of course pointless. Is there a solution to this?

Thanks for any help :)

Solution

Edit: I found out the answer. You can create 2 separate channels:

main_channel = pygame.mixer.Channel(0)
pause_channel = pygame.mixer.Channel(1)

load a different music onto each one

main_channel.play(pygame.mixer.Sound(mymusic1), loops=-1, fade_ms=5000)
pause_channel.play(pygame.mixer.Sound(mymusic2), loops=-1, fade_ms=5000)

pause the unwanted one

pause_channel.pause()

and call unpause()/ pause() whenever necessary