Attention during rehearsals (3)
I believe the answer is:
ear
'attention' is the definition.
(having someone's ear is having their attention)
'during rehearsals' is the wordplay.
'during' indicates a hidden word.
'EAR' is hidden within 'rehearsals'.
(Other definitions for ear that I've seen before include "Discernment musicians need" , "Organ involved with balance" , "Corn seed-holder" , "Organ inside heart" , "Lend one and listen" .)