Mate, don't listen to some of the ignorant responses you're getting in here.
I did English, Sociology and Media at A2 level and got 5 offers from 4 very respected Uni's. (All redbrick; In my zeal I applied to Sheffield twice ^___^).
If you ever feel like you must justify your chosen A-level to whatever Unis you're applying too, which you shouldn't, you could just mention in your personal statement something along the lines of "In one of my chosen subjects of Media Studies I found studying the different effects of music application within and outside diagesise in film particularily interesting." blah blah blah.
I'd say that Media Studies would compliment the study of music far better than a "harder subject" such as Chemisty or A2 Rocket Science.
Edit: Looking at your posted list of "Russel group" Universities, all of my offers were from such Universities. I.e - Leeds, Sheffield (x2), Manchester, Liverpool.
Although if you really are that worried I'd suggest taking Film Studies. As previously mentioned in this topic it is probably regarded with a little more respect than Media.