I feel like a broken record ...
ok, here's my point. Disregard the majority of music students and physics students, let's focus on the very top elite few in each subject.
Music: some kid has been playing guitar for 10 years. He could simply pick 4 performances, already know them like the back of his hand, not go under any intense rehearsals or trainings, and still get very good marks up around 90%. I know it happens. A lot of people are like this.
Physics: some kid is a mathematics genius and aboslutely loves physics. Obviously he has an advantage over the other kids who dont necessarily enjoy physics .. BUT, in order for this guy to get a high mark like 90%, he can't just rely on his plain talent and enjoyment of the subject, he'd still have to study his arse off to get a good mark.
This is the difference. It's easier for a lot of people to get a band 6 mark in music as it is for physic students to get a band 6 mark. I agree, SOME music students would work as hard as physics students to earn their mark, but what im saying is there is a high possability that a very talented musician could breeze through the performance exam with very little effort and still get high marks - this more or less IS NOT possibly for physics students.
I really hate bringing this into it, but you brought it up, and i must defend myself. I play drums. I chose 2 perf + core. All the songs i played were songs i previously knew and did not require any intense rehearsals (only with my backing musicians so that we were in sync). Obviously i cant present you with my exma marks to "prove" my theory correct, but if it means anything, for my trial performances, i got 9/10 (core), 17/20 (elective) and 18/20 (elective) .. and all 3 pieces were pieces i already knew and spent no specific time rehearsing for the exam. If i had of done that in my physics trial, i assure you i would not have passed. My point is it's very possibly for a music student to get high marks without trying, whereas it's not possible for a physics student to get high marks without trying hard. Thus the difference is clear, and physics gets scaled up. Now if you lot keep repeating the same arguments and misinterpretting what im saying, well, then i'll, er, be very cranky .. so there.