Surrey's top feature, musically (6)

I believe the answer is:

fringe

'surrey's top' is the definition.
'fringe' can be an answer for 'top' (thesaurus). I am unsure of the 'surrey's' bit.

I can't explain the remainder of the clue.

(Other definitions for fringe that I've seen before include "Border, outer part" , "Border; hair on brow" , "Perimeter" , "Rim" , "Finger (anag.)" .)

I've seen this clue in The Guardian.

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