Stage platform for a choir (5)
I believe the answer is:
riser
(Other definitions for riser that I've seen before include "A bit of a flight" , "Pipe for upward flow" , "Section of flight" , "an essential to flight" , "Vertical upward pipe" .)
I believe the answer is:
riser
(Other definitions for riser that I've seen before include "A bit of a flight" , "Pipe for upward flow" , "Section of flight" , "an essential to flight" , "Vertical upward pipe" .)