Call for more RE once, strangely (6)
I believe the answer is:
encore
'call for more' is the definition.
(I've seen this before)
're once strangely' is the wordplay.
'strangely' is an anagram indicator.
're'+'once'='reonce'
'reonce' with letters rearranged gives 'ENCORE'.
(Other definitions for encore that I've seen before include "Request to sing it again" , "Cry from the audience for more" , "Repetition of performance" , "Bonus" , "Bis!" .)