I do music, computer science and enterprise(not too sure if its similar to business) - as well as additional maths(+Cambridge international maths) double sciences, etc. I would say that music is a good subject if you are somewhat above grade 5 level because if you perform well enough(it doesn't have to be great), you will get full marks due to the difficulty of the piece. If you are good at composition, or have someone who can help you, it will make it easier. I'm horrible at composing but my teacher helps me improve. The listening is challenging at first because you have to know 8 pieces REALLY well. But, you will get the hang of it because you listen to the pieces so many times and also the questions are pretty standard - though sometimes its shockingly difficult as per the past papers, but then the boundaries will also be low(also you don't really need to know perfect music theory but the tests do have cadences/intervals/some vocab.. but it should be taught in school as well). Honestly music is fun... I'd just say that if you don't like computer science, don't choose it. The new syllabus is way harder than the previous one and honestly it gets boring sometimes(theory mostly). I prefer music over enterprise, but it is just a personal opinion - I'm not a big fan and sometimes dread going to class.
I have too much to say.. sorry!!