One who tapes the instrument (8)
I believe the answer is:
recorder
'one who tapes the instrument' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'who tapes the instrument' is the wordplay.
'who tapes' becomes 'rec' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'the instrument' becomes 'order' (order is a kind of instrument).
'rec'+'order'='RECORDER'
Can you help me to learn more?
(Other definitions for recorder that I've seen before include "Legal officer - wind instrument" , "Renaissance flute" , "Musical instrument or note-taker" , "found on the bench" , "A kind of flute or note-taker" .)