Composer of 'Messiah' and 'Elijah', apparently (6)
I believe the answer is:
handel
'composer' is the definition.
(George Frideric Handel)
'of messiah and elijah apparently' is the wordplay.
'of' indicates the answer is hidden within the clue.
'HANDEL' is hidden in the letters of 'messiah and elijah apparently'.
(Other definitions for handel that I've seen before include "German composer, lived in England" , "German composer of Messiah" , "German composer, George Frederick (1685-1759)" , "German baroque composer" , "Composer of the great ''Messiah''" .)