Tried composition on media executive (7)
I believe the answer is:
essayed
'tried' is the definition.
(to essay something is to attempt it)
'composition on media executive' is the wordplay.
'composition' becomes 'essay' (I've seen this before).
'on media executive' becomes 'ed' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'essay'+'ed'='ESSAYED'
Can you help me to learn more?
(Other definitions for essayed that I've seen before include "Attempted, strove" , "tested" , "Had a go" , "Made formal attempt" , "Tried (E, not A)" .)