Musical youth – a singing long-tailed tit

Today the adult long-tailed tits (Aegithalos caudatus) paid a visit on their regular rounds of the local gardens, accompanied by their very young offspring to show them our feeders and they all stayed around for a while. I love them especially when they arrive in their 'flighty' flocks and twitter away to each other. 

I hadn't seen a single long-tailed tit singing by itself, so I wonder whether it was 'singing for its supper,' like many very young birds, hoping its parents would bring food to stuff down its throats. It was on a low branch of a tree  hanging down over the roof of the cabin.