Some thespian orations could be grand (5)
I believe the answer is:
piano
'be grand' is the definition.
(thesaurus)
'some thespian orations could' is the wordplay.
'some' indicates the answer is hidden within the clue (some of the parts of the word are used).
'PIANO' is hidden in the letters of 'thespian orations could'.
(Other definitions for piano that I've seen before include "one of 6 [STEINWAYS]" , "p (mus.)" , "Softly (mus.)" , "Opposite of forte" , "Quiet (music)" .)