Frenchman, Ravel, composed sensation (6)
I believe the answer is:
marvel
'sensation' is the definition.
(thesaurus)
'frenchman ravel composed' is the wordplay.
'frenchman' becomes 'm' (abbreviation for Monsieur - like 'Mr').
'composed' is an anagram indicator.
'ravel' is an anagram of 'arvel'.
'm'+'arvel'='MARVEL'
(Other definitions for marvel that I've seen before include "Be filled with surprise or wonder" , "Be filled with wonder - something wondrous" , "Wondrous thing" , "Wonder at, be amazed" , "Cause of wonder" .)