Composer was a model in England originally (5)
I believe the answer is:
satie
'composer' is the definition.
(French composer Erik Satie)
'a model in england originally' is the wordplay.
'model' becomes 'T' (Ford Model T car).
'in' is an insertion indicator.
'england originally' becomes 'sie' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'a'+'t'='at'
'at' placed into 'sie' is 'SATIE'.
'was' acts as a link.
Can you help me to learn more?
(Other definitions for satie that I've seen before include "creative Frenchman" , "French composer (Trois Gymnopedies)" , "scorer" , "Erik -----, French early minimalist composer" , "Erik -, nineteenth to twentieth century French composer" .)