Final answer:
When the Army song is played, soldiers stand at attention, sing along, and may form up in a formation or salute if outdoors, reflecting military customs and traditions.
Step-by-step explanation:
During the playing of the Army song, soldiers typically stand at attention and sing along if in uniform. Depending on the formality of the occasion, they may also be required to rendezvous in formation or render the appropriate courtesies, such as saluting if outdoors. These actions are part of the military customs and traditions that instill discipline and esprit de corps among servicemembers. Customs like these are taught during basic training, as they are fundamental to military life and the building of a soldier's new identity within the armed forces. The playing of the Army song is not just a formality, but a moment of pride and reflection for soldiers, symbolizing the values and history that bind them together.