Hear about old and sad story (7)
I believe the answer is:
tragedy
'sad story' is the definition.
(I've seen this before)
'hear about old' is the wordplay.
'hear' becomes 'try' (to hear or try a case in the legal sense).
'about' is an insertion indicator.
'old' becomes 'aged' (similar in meaning).
'try' enclosing 'aged' is 'TRAGEDY'.
'and' is the link.
(Other definitions for tragedy that I've seen before include "Terribly sad thing" , "Calamity, disaster" , "shocking event" , "sad event" , "Calamity as in sad play" .)