Like a mob being controlled with strange instrument (10)
I believe the answer is:
kettledrum
'instrument' is the definition.
(I know that kettledrum is a type of percussion instrument)
'like a mob being controlled with strange' is the wordplay.
'like a mob being controlled' becomes 'kettled' (the police might kettle a mob of people).
'with' is a charade indicator (letters next to each other).
'strange' becomes 'rum' (synonyms).
'kettled'+'rum'='KETTLEDRUM'
(Other definitions for kettledrum that I've seen before include "one beaten with sticks" , "17 instrument" , "Orchestral instrument" , "Part of kitchen" , "thing to produce tattoo" .)