Musical instrument in best performance shown with hesitation (8)
I believe the answer is:
recorder
'musical instrument' is the definition.
(I know that recorder is a type of pipe)
'best performance shown with hesitation' is the wordplay.
I cannot quite understand how this works, but
'best' could be 'record' (similar in meaning) and 'record' is found within the answer.
'hesitation' could be 'er' (sound made while hesitating - um, er) and 'er' is found within the answer.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
'in' acts as a link.
Can you help me to learn more?
(Other definitions for recorder that I've seen before include "One taking down notes" , "The one who takes notes and a tubular wind instrument" , "Woodwind instrument; official" , "Wind instrument - historian, perhaps" , "Wind instrument - instrument for transferring sound to tape" .)