Silence after South African band (4)
I believe the answer is:
sash
'band' is the definition.
(sash is a kind of band)
'silence after south african' is the wordplay.
'silence' becomes 'sh' ('sh' is said to tell someone to be silent).
'after' means one lot of letters go next to another.
'south african' becomes 'sa'.
'sh' after 'sa' is 'SASH'.
(Other definitions for sash that I've seen before include "Long strip of material - window frame" , "Style of window" , "Girdle" , "Item of clothing - frame for glass" , "Decorative belt" .)