Secondly the march Men in Gray was not written to glorify the veterans of the Confederacy.
"N.K. Brahmstadt was a high school band director in Milwaukee, WI and composed this march for the Milwaukee Letter Carriers Union Band. The "men in gray" refers to the carriers of the United States Post Office. The Milwaukee Letter Carriers Band still exists today and performs in the Milwaukee area."
Furthermore, even if you were to play a march such as General Lee (which my JV HS band is playing) IT DOESN'T F****** MATTER. Music is music.