Nuts about Beethoven's Third, beginning to rave over conductor (7)
I believe the answer is:
maestro
'conductor' is the definition.
(I've seen this before)
'nuts about beethoven's third beginning to' is the wordplay.
'nuts' becomes 'mast' (mast is the nuts of forest trees).
'about' is an insertion indicator.
'beethoven's third' becomes 'e' (3rd letter of 'beethoven').
'beginning to' becomes 'ro' (I am not sure about this - if you are sure you should believe this answer much more).
'mast' placed around 'e' is 'maest'.
'maest'+'ro'='MAESTRO'
'rave over' acts as a link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for maestro that I've seen before include "musical genius" , "car" , "Highly talented figure in a given field" , "Virtuoso" , "ace" .)