A group of three patriotic songs is included (4)
I believe the answer is:
trio
'a group of three' is the definition.
(I've seen this in another clue)
'patriotic songs is included' is the wordplay.
'is included' indicates the answer is hidden within the clue (I've seen 'including' mean this).
'TRIO' is hidden in the letters of 'patriotic songs'.
(Other definitions for trio that I've seen before include "Riot (anag)" , "Bee Gees, Supremes or Andrews Sisters, say" , "Group of Magi?" , "Piece for three players" , "Three together" .)