Platform with men turning up to play guitar? (7)
I believe the answer is:
rostrum
'platform' is the definition.
(rostrum is a kind of platform)
'with men turning up to play guitar?' is the wordplay.
'with' says to put letters next to each other.
'men' becomes 'or' (I've seen this in other clues).
'turning up' says the letters should be written backwards.
'to play guitar?' becomes 'strum' (I've seen this before).
'or' in reverse letter order is 'ro'.
'ro'+'strum' is 'ROSTRUM'.
(Other definitions for rostrum that I've seen before include "Platform for orchestra conductor" , "beak" , "Podium" , "Platform for public speaking" , "At which one may conduct" .)