Courage Under Fire is a song from the Shovel Knight soundtrack.
Music Sheet #8 can be found in Armor Outpost, Room 1. In the Armor Outpost, climb the rooftops. There are multiple methods to reach it, including shovel dropping the sign outside the hat shop and then jumping over, or dropping out of the airship 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!"