I don't know the answer to your question, but I can shed light on its use by General Neyland to great psychological effect. For those of you who want a citation/link for the narrative I am about to share, please fast-forward to the 34:33 mark of this documentary about Neyland (
https://www.youtube.com/watch?v=cBWJgoBZTeM). This account is provided by Hugh Faust, who played on the 1928-29 teams with Bobby Dodd and Gene McEver. Faust later served as an assistant coach under Neyland. According to Faust, Neyland was preparing to give his pre-game address prior to the Vols 1951 Cotton Bowl game with Texas. Neyland sensed that his team was keyed up, indeed a bit too much for his taste. He heard the strains of the Tennessee Waltz wafting through the locker room windows that opened onto the concourse. He then cupped his hand to his ear, paused and, without saying a word, began to dance a waltz by himself. For this disciplined military man to do so publicly struck the team as so out of character that they stared in disbelief for a few seconds before erupting into a prolonged round of laughter. Without saying a word, Neyland cut through the tension that hung over his team and then proceeded to give his pre-game remarks.
Neyland again employed humor as a psychological weapon at halftime. I regret that I cannot recall my source for this incident, but, perhaps, its details will trigger the memory of some fellow gray beard. In any event, Tennessee then trailed Texas 14-7. Neyland basically told his team that weve got them right where we want them. We are better conditioned than they are, they will have to handle the ball a lot [in these rainy conditions] and, given how much they like to pass, they are bound to have a turnover or two. Neyland had someone posted near the locker room door to inform him when the Longhorns were ready to return to the field. As they filed past Tennessees locker room, a carefully orchestrated burst of laughter erupted from the Volunteers, one intended to convey the message that we arent the slightest bit disheartened, were confident and were still loose. Tennessee proceeded to win that game 20-14 and the general consensus was that General Neyland had never been happier about any single win than that Cotton Bowl victory over Texas.