Singer ____ Hayes (5)
I believe the answer is:
isaac
'singer hayes' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for isaac that I've seen before include "- Asimov, sci-fi writer" , "Jacob's father" , "Jewish name?" , "-- Asimov, science fiction writer" , "& 17 Down SF author" .)