In his travels, he wrote many notes (5)
I believe the answer is:
ravel
'he wrote many notes' is the definition.
Although both the answer and definition are singular nouns, I can't see how they can define each other.
'in his travels' is the wordplay.
'in' says the answer is hidden in the clue.
'RAVEL' is hidden in the letters of 'his travels'.
Can you help me to learn more?
(Other definitions for ravel that I've seen before include "Composer of the orchestral piece, Bolero, d. 1937" , "Tangle - untangle - French composer, d. 1937" , "Tangle or become tangled" , "French composer, Maurice (1875-1937)" , "Entangle - French composer, d. 1937" .)