Entrance for poor singers (7)
I believe the answer is:
ingress
'entrance' is the definition.
(I know that entrance can be written as ingress)
'poor singers' is the wordplay.
'poor' indicates anagramming the letters.
'singers' with letters rearranged gives 'INGRESS'.
'for' is the link.
(Other definitions for ingress that I've seen before include "right of entry" , "Admission" , "Entrance, access" , "Means of access" , "permission to enter" .)