Whereupon the players have no seats? (9)
I believe the answer is:
bandstand
'whereupon the' is the definition.
I can't tell whether this defines the answer.
'players have no seats?' is the wordplay.
'players' becomes 'band' (group playing music).
'have' is a charade indicator (letters next to each other).
'no seats?' becomes 'stand' (stand is a kind of seats. I am not sure about the 'no' bit.).
'band'+'stand'='BANDSTAND'
Can you help me to learn more?
(Other definitions for bandstand that I've seen before include "Outdoor music platform" , "place to play?" , "Outdoor platform for musical performances etc" , "Outdoor concert stage" , "park feature?" .)