At 0:09 seconds, the main unchanging baseline that was the most interesting part of the piece, because it was the only sound, gets joined by a higher-pitched and more quickly varying melody. Because of this, there quickly becomes a distinction between foreground and background within the piece with the two streams of sound, one lower and unvarying, and the other following a short looping melody that changes more quickly and is at a higher pitch. Again at about 0:19 seconds, a beat gets added to the music, and while it doesn't change the higher-pitched melody in the foreground, it gets added to the background and drowns out the original background because of volume, even though all streams are still present in the music.