They aren't all grand to play (6)
I believe the answer is:
pianos
'they' is the definition.
Both the answer and definition are plural nouns.
Perhaps there's an association between them I don't understand?
'aren't all grand to play' is the wordplay.
I cannot really see how this works, but
'play' could be 'no' (no or noh is a type of Japanese theatre) and 'no' is located in the answer.
The remaining letters 'pias' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for pianos that I've seen before include "Musical instruments like Steinways" , "Hammer-based instruments" , "Hammer and strings instruments" , "Chordophones with keys" , "Stringed instruments" .)