Source for thin single core shielded cable in the UK?

[peskywinnets]

I'm having diffs sourcing some thin single core shielded cable - it's the type of stuff normally used for guitar cavity wiring ....must be shielded, preferably rather flexible (I never know the name of the outer sheath material that yields nice flexible cable!) - any top tips ....supplier, part number, URL etc - aye, that'd be grand.

Many thanks
peskywinnets.