What's made by no one on stage, but just outside, so very loud? (6,3)
I believe the answer is:
noises off
'what's made by no one' is the definition.
I don't know anything about this answer so I cannot tell whether this works.
'stage but just outside so very loud?' is the wordplay.
'stage' becomes 'noi' (I can't justify this - if you can you should give a lot more credence to this answer).
'but' becomes 'save' (I've seen this in another clue).
'just outside' says to hollow out the word (remove centre letters) (just the outside letters of the word).
'very loud?' becomes 'ff' (musical abbreviation).
'save' with its centre taken out is 'se'.
'noi'+'se'+'so'+'ff'='NOISES OFF'
'on' acts as a link.
Can you help me to learn more?
(Other definitions for noises off that I've seen before include "Stage direction" , "Direction of play" .)