Harp of Rassilon
From Tardis Wiki, the free Doctor Who reference
The Harp of Rassilon is a key to a secret door in the High Council chambers. The door opened into a room that once held a Time Scoop. (DW: The Five Doctors) There is a painting beside where the Harp was kept, it is a painting of a piece of music known as Rassilon's Lament. (NA: Blood Harvest)