Unidentified small white+grey bird white stripe on head

Observation - Unidentified small white+grey bird white stripe on head. Description: A pair of small sparrow-sized birds in my garden for just half a minute - too little to photograph them. Lovely looking, very pale grey bodied with grey and white head in horizontal stripes, and a prominent white stipe back over the centre of the head.

A pair of small sparrow-sized birds in my garden for just half a minute - too little to photograph them. Lovely looking, very pale grey bodied with grey and white head in horizontal stripes, and a prominent white stipe back over the centre of the head. Seemed to hover almost humming-bird like for a moment by a window pane. Quick moving, gone in moments.
Two together. Have never seen anything like them in my life before.

Nearest I can find is White-Crowned Sparrow: but all the photos of those show a much more prominent black head striping than I saw: this was an altogether paler colouring: a winter juvenile perhaps? Some winter photos do look fairly similar, though always more brown on the wings than I saw.

Also a bit like this - the Clay-Coloured Sparrow:
http://www.birds.cornell.edu/crows/claycolor.htm
- but again, there was not really any brown on the ones I saw, at all, while it is prominent in this photo. The ones I saw were only middle greys and white, nothing brownish at all (unless memory failing me).

Would be intruigued to know if anyone knows what this was.
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AH.... think I've found it: might have been a juvenile long-tailed tit - this photo is quite like what I saw:
http://www.kimcomania.co.uk/garden/Long-tailed%20tit.jpg

A bit paler than that but perhaps a juvenile. Lovely: first one I've ever seen. Saw both my first-ever goldcrest and goldfinch recently - what a treat.