Putting together popular musical lacking orchestral opening (7)
I believe the answer is:
linking
'putting together' is the definition.
('link' can be a synonym of 'put together')
'popular musical lacking orchestral opening' is the wordplay.
I cannot quite understand how this works, but
'popular' could be 'in' ('in' can mean trendy) and 'in' is located in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for linking that I've seen before include "Joining" , "Connecting, putting together" , "Connecting, fastening" .)