Be there at the beginning and finale (6)
I believe the answer is:
attend
'be there' is the definition.
(I've seen this before)
'at the beginning and finale' is the wordplay.
'beginning' suggests taking the first letters.
'and' is a charade indicator (letters next to each other).
'finale' becomes 'end' (I've seen this before).
The initial letter of 'the' is 't'.
'at'+'t'+'end'='ATTEND'
(Other definitions for attend that I've seen before include "Be there ? pay attention" , "minister" , "Be present at, turn up" , "Listen carefully" , "Follow" .)