Composer of the manual for the Spanish (6)
I believe the answer is:
handel
'composer' is the definition.
(George Frideric Handel)
'the manual for the spanish' is the wordplay.
'the manual for' becomes 'hand' (I am not sure about this - if you are sure you should believe this answer much more).
'the spanish' becomes 'el' ('the' in Spanish).
'hand'+'el'='HANDEL'
'of' acts as a link.
Can you help me to learn more?
(Other definitions for handel that I've seen before include "Water Music composer, d. 1759" , "German composer, lived in England" , "Composer of Messiah, d.1759" , "German scorer" , "British composer of German birth, the 'father of the oratorio'" .)