Colonel Bogey March

The  was a tune which the Fourth Doctor liked to whistle. (TV: The Face of Evil, The Talons of Weng-Chiang, The Invasion of Time, Destiny of the Daleks) The Brigadier also whistled it when he was leading an undercover infiltration of Stangmoor Prison. (TV: The Mind of Evil)

Behind the scenes
The piece was never named on television, but it was unmistakably performed by Tom Baker, particularly at the top of episode one of The Face of Evil. In fact, it features prominently on BBC Video's DVD trailer for the story.