Officer in photo with old wind instrument (7)
I believe the answer is:
piccolo
'wind instrument' is the definition.
(piccolo is a kind of wind instrument)
'officer in photo with old' is the wordplay.
'officer' becomes 'col' (short for colonel).
'in' is an insertion indicator.
'photo' becomes 'pic' (short for picture).
'with' says to put letters next to each other.
'old' becomes 'o' (abbreviation).
'pic'+'o'='pico'
'col' going into 'pico' is 'PICCOLO'.
(Other definitions for piccolo that I've seen before include "Smallest of the flute family" , "Instrument (meaning "little")" , "Little flute" , "Instrument of the flute family" , "Small high-pitched flute" .)