Music at my school is great and very practical, although the written exam is pretty difficult. It depends a lot on your exam board - if you do Edexcel then you have to learn lots of set pieces and write short essays about them in the exam which some people find boring, if you do OCR the focus is more on knowing the features of different styles, and for AQA I don't think you do either, just aural skills (which you get a lot of with all exam boards I should add). As a grade 5 musician I found the performance section quite easy to get full marks in, and if you have a basic level of music theory you are likely to find yourself at a big advantage.
As for your other subjects, I'm not studying any of them myself but I have three friends doing ICT and I know they would tell you to avoid it like the plague and that the amount of coursework and write-ups you have to do is insane. They're bright, hard-working students but are always having to miss PE and go in after school to do extra ICT just because there's so much work (although that does seem to be the case with many practical subjects such as art and drama).