They can be Horatian (4)
I believe the answer is:
odes
'they can be horatian' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for odes that I've seen before include "verse" , "Lyrical poems" , "Lyric poems" , "To a Skylark, To a Nightingale etc" , "Keats was fond of them" .)