A drum was a musical instrument.
The Doctor was an avid fan of drummers and could play the instrument himself. In one instance, the Doctor's first four incarnations attempted to form a band but found difficulties as they all wanted to play the drums. (COMIC: Day of the Tune) The Eleventh Doctor later noted a fondness for Ringo Starr and wondered why few others thought of him highly. (GAME: City of the Daleks) The Twelfth Doctor nearly played the drums during his appearance on Battle of the Bands Beyond the Stars, but was interrupted by Clara Oswald cutting the power. (COMIC: One! Two! Three! Four! To Doomsday)
The Master constantly heard the sound of drums in his head ever since he looked into the Untempered Schism as a boy. (TV: The Sound of Drums) This noise was implanted by Rassilon in his efforts to escape the final day of the Last Great Time War, fearing the absolute destruction of Gallifrey. (TV: The End of Time) The Master played the drums in Gallifrey Academy Hot Five. (PROSE: Deadly Reunion) The "Saxon" Master was the drummer in a band consisting of five incarnations of himself. (COMIC: The Abominable Showmen, The Five Masters)