Band introduces new material (5)
I believe the answer is:
linen
'material' is the definition.
(linen is a kind of material)
'band introduces new' is the wordplay.
'band' becomes 'line'.
'introduces' says to take the initial letters (I've seen 'introduced' mean this).
The first letter of 'new' is 'n'.
'line'+'n'='LINEN'
(Other definitions for linen that I've seen before include "Sheets, cloths, napkins etc" , "Underclothes" , "bedsheets?" , "sheets, perhaps" , "Such paper" .)