American composer introducing Spanish article into GS (5)
I believe the answer is:
glass
'american composer introducing' is the definition.
I can't judge whether this defines the answer.
'spanish article into gs' is the wordplay.
'spanish article' becomes 'las' (I've seen this in another clue).
'into' is an insertion indicator.
'las' inserted into 'gs' is 'GLASS'.
Can you help me to learn more?
(Other definitions for glass that I've seen before include "Drink container" , "Tumbler or flute?" , "Drinking vessel" , "Perhaps schooner" , "Transparent substance" .)