Those fronting band include fab four hit (4)
I believe the answer is:
biff
'hit' is the definition.
(I know that biff is a more specific form of the action hit)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for biff that I've seen before include "Hard blow with fist" , "Punch" , "strike" .)