Does Cambridge care about irrelevant A-levels?

I’m taking maths, further maths, physics and music. It’s pretty clear which is the irrelevant one..

I’m hoping to apply for maths (with physics) next year at Cambridge and just wondering if they would want a specific grade in it?

Also, if I drop it in year 13 to focus on my main subjects, will that make my application look weaker because it looks like I can’t handle the workload?