Crossword Genius

Transmitting booming Tallis aria frequently (2,3)

Ross

I believe the answer is:

on air

I'm a little stuck... Click here to teach me more about this clue!

'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?" .)

I've seen this clue in The Independent.
Want a hint initially instead of a full solution? Install my app