To the listener, a commanding quartet (7)
I believe the answer is:
foremen
'the listener a commanding quartet' is the definition.
I can't tell whether this definition defines the answer.
'to' is the wordplay.
I cannot really see how this works, but
'to' could be 'for' and 'for' is located in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for foremen that I've seen before include "Overseers" , "They supervise other workers" , "Persons in charge" , "Workers' leaders" , "Resembling a bird" .)