You're a Grand Old Flag is a children's song/4th of July song/patriotic song that pays tribute to the US flag. In the Barney franchise, it first appeared in Barney Goes to School.
Lyrics
You're a grand old flag
You're a high flying flag
And forever in peace may you wave.
You're the emblem of
The land I love.
The home of the free and the brave!
Every heart beats true
'neath the red, white, and blue,
where there's never a boast or brag.
But should auld the acquaintance be forgot,
keep your eye on the grand old flag!