King Henry is missing from composer's characters (4)
I believe the answer is:
lear
'king' is the definition.
(King Lear)
'henry is missing from composer's characters' is the wordplay.
I cannot really see how this works, but
'from' could be 'e' (I've seen this in other clues) and 'e' is present in the answer.
The remaining letters 'lar' is a valid word which might be clued in a way I don't see.
This may be the basis of clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for lear that I've seen before include "troubled king" , "Role at Stratford" , "Humorist, Edward --" , "writer of comic verse" , "Playful king and writer of nonsense verse" .)