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' indicates the answer is hidden within the clue (some 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" .)