Mixed singing Chiffchaff

This Chiffchaff was recorded at Stewartby Lake on 1st May by Martin Palmer.  Martin comments:
"The Chiffchaff was singing at Stewartby Lake c2.15pm, 1/5/13 with mixed Willow Warbler into its Chiffchaff vocals and was recorded by me just along from the Green Lane sluice, some 50m or so towards the sailing club corner – the bird was showing well and was quite clearly merely a Common Chiffchaff with dark legs and feet and no bright yellow in any of its plumage – so just Chiffy not a hybrid I’d say and it certainly didn’t show any Iberian tendancies! Worth listening out for if you’re down that way"