In Paris, my old box contains top-class speech (9)
I believe the answer is:
monologue
'speech' is the definition.
(monologue is a kind of speech)
'in paris my old box contains top-class' is the wordplay.
I cannot really see how this works, but
'old' could be 'o' (common abbreviation eg in OE for Old English) and 'o' is present in the answer.
'top-class' could be 'u' (as in U and non-U speech) and 'u' is found within the answer.
'box' could be 'loge' ('loge' can be a synonym of 'box') and 'loge' is present in the leftover letters.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for monologue that I've seen before include "speaking without interruption" , "Soliloquy" , "Long solo speech" , "Long uninterrupted speech" , "Long and tedious speech" .)