As other commenters have pointed out, this is a C64 controlling an MP3 player.
People old enough to remember the late 1990s / early 2000s might recall that back then it was popular, too, to hook up an external MP3 decoder, e.g., to the parallel port; so that the PC's CPU would not be at 100% just for playing MP3 music.
People old enough to remember the late 1990s / early 2000s might recall that back then it was popular, too, to hook up an external MP3 decoder, e.g., to the parallel port; so that the PC's CPU would not be at 100% just for playing MP3 music.