Musical entertainment viewed in the Adelphi originally? (5)
I believe the answer is:
evita
'musical' is the definition.
(I've seen this before)
'entertainment viewed in the adelphi originally?' is the wordplay.
'originally?' says to take the initial letters (I've seen 'originally' mean this).
The first letters of 'entertainment viewed in the adelphi' is 'EVITA'.
(Other definitions for evita that I've seen before include "Well-known musical" , "1978 Lloyd Webber musical" , "Famous musical" , "Stage musical" , "Nineteen Dn musical" .)