Musical bag, lock container (7)
I believe the answer is:
hairnet
'lock container' is the definition.
The definition and answer can be both man-made objects as well as being singular nouns.
Perhaps there's a link between them I don't understand?
'musical bag' is the wordplay.
'musical' becomes 'hair' (1960s musical).
'bag' becomes 'net' (I've seen this in other clues).
'hair'+'net'='HAIRNET'
Can you help me to learn more?
(Other definitions for hairnet that I've seen before include "keeper of locks" , "It may keep locks" , "Cover for head" , "It keeps locks in place" , "It protects locks" .)