He composed some incredible harmonies (5)
I believe the answer is:
lehar
'he composed' is the definition.
The definition suggests a singular noun which matches the answer.
'some incredible harmonies' is the wordplay.
'some' says the answer is hidden in the clue (some of the parts of the word are used).
'LEHAR' can be found hidden inside 'incredible harmonies'.
Can you help me to learn more?
(Other definitions for lehar that I've seen before include "Franz . . . . . composed 'The Merry Widow'" , "He scored" , "Operettist" , "Viennese composer" , "Operetta composer" .)