Staff do nothing about instrument (8)
I believe the answer is:
mandolin
'instrument' is the definition.
(mandolin is a kind of instrument)
'staff do nothing' is the wordplay.
'staff' becomes 'man' (manning is a kind of staffing).
'do nothing' becomes 'dolin' (I can't justify this - if you can you should believe this answer much more).
'man'+'dolin'='MANDOLIN'
'about' is the link.
Can you help me to learn more?
(Other definitions for mandolin that I've seen before include "Musical instrument like a small guitar" , "one's deployed in the kitchen" , "Almond in the stringed instrument, oddly" , "vegetable slicer" , "it has strings attached" .)