Marx's lost love for music producer (4)
I believe the answer is:
harp
'music producer' is the definition.
Although both the answer and definition are singular nouns, I don't see how they can define each other.
'marx's lost love' is the wordplay.
'marx' becomes 'harpo' (Harpo Marx).
'lost' suggests deleting specific letters.
'love' becomes 'o' (In tennis, 'love' means 'zero').
'harpo' with 'o' taken away is 'HARP'.
'for' is the link.
Can you help me to learn more?
(Other definitions for harp that I've seen before include "Musical symbol" , "semitone higher, abandoning intro" , "Large plucked instrument" , "''The ... that once through Tara's halls'' (4)" , "Talk tiresomely using upright musical instrument" .)