When I begin to sing , watch that window . " He retreated hastily to a position on the main drive , and began in a deep roar , coupled with an unsteady gait , the following ditty : I am a Soldier A jolly British Soldier ; You can see that I 'm a Soldier by my feet … It had been a favourite on the gramophone in Tuppence 's hospital days .
He stayed firmly in place while he sang , his voice shrill and unwavering .