Hard to follow some elite military band (4)
I believe the answer is:
sash
'band' is the definition.
(a band of material)
'hard to follow some elite military' is the wordplay.
'hard' becomes 'h' (abbreviation used in pencil classifications).
'to follow' is a charade indicator (letters next to each other) (some letters go after or follow others).
'some elite military' becomes 'SAS' (Special Air Service in UK army).
'h' put after 'sas' is 'SASH'.
(Other definitions for sash that I've seen before include "Strip of cloth worn round the waist" , "Decoration for the twelfth" , "Frame for a windowpane" , "seen hanging around Miss World?" , "(Uniform) strip; window-frame" .)