Danish prince losing head about king’s band (6)
I believe the answer is:
armlet
'king's band' is the definition.
'armlet' can be an answer for 'band' (armlet is a kind of band). I am not certain of the 'king's' bit.
'danish prince losing head about' is the wordplay.
'danish' becomes 'r' (I can't explain this - if you can you should give a lot more credence to this answer).
'prince' becomes 'hamlet' (Prince of Denmark in Shakespeare's Hamlet).
'losing head' means to remove the first letter.
'about' means one lot of letters goes inside another.
'hamlet' with its first letter taken away is 'amlet'.
'r' placed within 'amlet' is 'ARMLET'.
Can you help me to learn more?
(Other definitions for armlet that I've seen before include "Martel (anag.)" , "Band worn for decoration" , "Small band" , "brassard" , "Elm rat (anag)" .)