The One and Only ? That’s music to try to reproduce (4,4)
I believe the answer is:
soul mate
'the one' is the definition.
(both can mean someone's perfect romantic partner)
'only ? that's music to try to reproduce' is the wordplay.
I cannot really see how this works, but
'music' could be 'soul' (type of music) and 'soul' is present in the answer.
The remaining letters 'mate' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
'and' is the link.
Can you help me to learn more?
(Other definitions for soul mate that I've seen before include "lover?" , "One's ideal partner" , "Person sharing deep affinity" , "perfect partner" , "Person ideally suited to self, spiritual pal" .)