Thrash metal about right for band (6)
I believe the answer is:
armlet
'for band' is the definition.
(armlet is a kind of band)
'thrash metal about right' is the wordplay.
'thrash' is an anagram indicator (I've seen this in other clues).
'about' is an insertion indicator.
'right' becomes 'r' (common abbreviation).
'metal' anagrammed gives 'amlet'.
'amlet' going around 'r' is 'ARMLET'.
(Other definitions for armlet that I've seen before include "brassard" , "sort of band" , "Martel (anag.)" , "Band on limb" , "branch" .)