Short story about powdered substance provided by some rock bands (4)
I believe the answer is:
talc
'powdered substance provided by some rock bands' is the definition.
'short story about' is the wordplay.
'short' means to remove the last letter.
'story' becomes 'tale' ('tale' can be a synonym of 'story').
'about' becomes 'c' (abbreviation for 'circa'**).
'tale' with its final letter removed is 'tal'.
'tal'+'c'='TALC'
(Other definitions for talc that I've seen before include "Powdered mineral" , "Softest mineral on Mohs hardness scale" , "Perfumed drying powder" , "soother" , "Toilet powder - mica" .)