Hail to the Chief

"Hail to the Chief" was the title of a piece of music from Earth. It was traditionally played upon the entrance of a President of a nation-state into a public gathering.

The Doctor, fresh from portraying the President of Earth within The Adventures of Captain Proton holoprogram in 2375, remarked to Tom Paris and Harry Kim, "Isn't anyone going to sing "Hail to the Chief"?"