I wonder if, rather than focusing purely on the department's reputation, you might be better considering whether it is a 'good' department and a 'good' university for
you.
Do you like the course?
Do you like the type(s) of music they focus on?
Would you get the playing/preformance/composition/other opportunities which you want?
Would the course require you to do a lot of things you don't enjoy?
Is it an area you think you'd be happy to live in?
Do you think you'd be happy spending 3-4 years of your life there?
Regardless of how 'good' a department' or university's reputation is, it won't suit everyone and however 'good' a place is in terms of it's reputation you won't do as well as you can on the course if you are unhappy with the other areas of your life (e.g. you hate the place). Similarly, if (for example) you want to do a lot of jazz then somewhere with a great classical tradition and limited jazz provision probably wouldn't suit you, even if it had the most outstanding reputation ever.
Hope you enjoy whatever you decide.