Military drill syllable

• March intonation
• "___ two three four" (military cadence)
• Driller's syllable
• Marching start?
• Drill sergeant's call
• "___, two, three, four!" (marching shout)
• "___, two, three, four!" (marching words)
• Marching syllable

Wiktionary Word definitions in Wiktionary
interj. The first beat of a 4/4 military cadence, commanding either the lead-off step in a march or some other action.