The band later played the number in it (6)
I believe the answer is:
armlet
'the band' is the definition.
(armlet is a kind of band)
'later played the number in it' is the wordplay.
'played' is an anagram indicator.
'the number' becomes 'm' (M is an example**).
'in it' means one lot of letters goes inside another.
'later' anagrammed gives 'arlet'.
'arlet' going around 'm' is 'ARMLET'.
(Other definitions for armlet that I've seen before include "Elm rat (anag)" , "Form of bracelet" , "Martel (anag.)" , "Band for wearing" , "Band on limb" .)