In addition to Flourish you have to play I Vow to Thee My Country for a grade 4.
I also believe Glaciers is a very playable piece as long as you have a solid flute soloist and good horns.
Has anyone played the following pieces? If so, please let me know if they're playable by a fairly young high school band.
Flourish for wind band
Arirang and Akombo
For heaven and the future
Scenes from terezin