Chemistry tends to be an assumed knowledge thing for quite a few courses, and it's in both uni bio and phys (not as much in phys though). Earth and Enivornmental Science and Geography I'd imagine are more similar than you think- earth goes more into the science behind the environment, whilst Geo is more about the human impact on the environment / management strategies on how to preserve ecosystems + human geography stuff.
Which music course are you doing?
Both music and society have major projects in year 12, FYI