Transmitting booming Tallis aria frequently (2,3)
I believe the answer is:
on air
'transmitting' is the definition.
(eg transmitting on the radio)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for on air that I've seen before include "Broadcasting studio sign" , "put out" , "How one walks when elated" , "Walk in delight here" , "In the process of broadcasting - floating aloft?" .)