Born romantic: a hundred music scores all begun by one composer (6)
I believe the answer is:
brahms
'composer' is the definition.
(I know that Brahms is a composer)
'born romantic a hundred music scores all begun by one' is the wordplay.
'born romantic' becomes 'br' (this might be a standard abbreviation of which I'm unaware).
'all begun by one' says to take the initial letters (only one letter).
The first letters of 'hundred music scores' is 'hms'.
'br'+'a'+'hms'='BRAHMS'
Can you help me to learn more?
(Other definitions for brahms that I've seen before include "He scored" , "Composer of A German Requiem" , "Composer (associated with Liszt?)" , "German Romantic composer" , "19th century German composer, known for Lullaby" .)