He composed The Spanish Swimmer (5)
I believe the answer is:
elgar
'he composed' is the definition.
The definition suggests a singular noun which matches the answer.
'the spanish swimmer' is the wordplay.
'the spanish' becomes 'el' ('the' in Spanish).
'swimmer' becomes 'gar' (type of gar).
'el'+'gar'='ELGAR'
Can you help me to learn more?
(Other definitions for elgar that I've seen before include "13 composer, 1857-1934" , "Enigma Vars. composer" , "Land of Hope and Glory composer" , "Glare at composer of 'The Dream of Gerontius'" , "Glare at great English composer" .)