How can I find out which state schools have music/sports places?

[temporary]

I am in London, and I know of very local ones, but is there a way of finding out about out of area schools? Or is it just a word of mouth thing?

Look at the secondary admissions booklets for the LAs concerned. You will find them on their website. The booklets will tell you the admission criteria for each school. If any of them have music or sports places that will be stated in the admission criteria.