Maestro no longer seen on the buses (9)
I believe the answer is:
conductor
I believe this clue is a double definition.
'maestro' is the first definition.
'no longer seen on the buses' is the second definition.
(conductors were once employed on buses)
(Other definitions for conductor that I've seen before include "See 6" , "Musician" , "Train guard" , "who may wave his hands about?" , "Orchestral director" .)