Choir performed on the day for a flower (6)
I believe the answer is:
orchid
'flower' is the definition.
(I know that orchid is a type of flower)
'choir performed on the day' is the wordplay.
'performed' indicates anagramming the letters.
'on' says to put letters next to each other.
'the day' becomes 'd' (abbreviation for day).
'choir' is an anagram of 'orchi'.
'orchi'+'d'='ORCHID'
'for a' acts as a link.
(Other definitions for orchid that I've seen before include "Chord I play for the flower" , "Family of flowers with unusual shapes and beautiful colours" , "Plant with showy flowers" , "Plant with showy flower" , "Cor! hid in the flower" .)