It's a good idea to take separate or "triple" sciences as I know them, if you are considering taking a science for A Level. Some sixth forms will allow to study 1, maybe 2 sciences at A Level without having done separate sciences at GCSE.
It depends what subject you're serious about. If you're looking to Music A Level, GCSE music is pretty much a must. A Level sciences might be more flexible, but again, a solid foundation at GCSE would be helpful.
I'd say on balance, to go for sciences, unless you're only looking to take about 1 science for A Level OR are interested in continuing Music to A Level.