Courage Under Fire is a music from the Shovel Knight soundtrack. This is the outdoor theme of the Armor Outpost. It is Music Sheet #8 in Shovel of Hope. It can also be listened to in Sound Test after completing either that campaign or Plague of Shadows once.
Music Sheet #8 can be found in the Armor Outpost, on the rooftops near the entrance. There are multiple methods to reach it, including Shovel Droping the sign outside the hat shop and then jumping over, or dropping out of the Aerial Anvil from above.
"Your trials are far from over, but for now, you can rest your shovel."
- "Bard: Let's see here... Oh, you found "Courage Under Fire"! Such a surly lot, those blacksmiths. All doom and gloom. At least they pay decently!"