Old jazz uncovered in dad's open space (5)
I believe the answer is:
plaza
'open space' is the definition.
(I've seen this before)
'old jazz uncovered in dad's' is the wordplay.
'old' becomes 'l' (I can't justify this - if you can you should believe this answer much more).
'uncovered' says to take the centre.
'in' is an insertion indicator.
'dad' becomes 'pa' (synonyms).
The centre of 'jazz' is 'az'.
'l'+'az'='laz'
'laz' placed within 'pa' is 'PLAZA'.
(Other definitions for plaza that I've seen before include "Public square - shopping centre" , "Public square, as in Spanish town" , "Hotel" , "Public square or market" , "Sp. square, market-place" .)