All the numbers to be analysed within the uplifting confines of Sonata da Chiesa (4)
I believe the answer is:
data
'all the numbers to be analysed within the uplifting confines of sonata' is the definition.
I can't tell whether this defines the answer.
'da chiesa' is the wordplay.
'chiesa' becomes 'ta' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'da'+'ta'='DATA'
Can you help me to learn more?
(Other definitions for data that I've seen before include "Pieces of information" , "Collection of bits of information" , "Collection of items of information" , "tables, perhaps" , "Listed facts" .)