Song (Overture)
From Tardis Wiki, the free Doctor Who reference
Though it was thought of as having Romanian Gypsy origins, a song was actually accidentally brought through the Cardiff Rift by an unnamed species. It became infamous on Earth for making everyone who sang it commit suicide.
When a club singer sang the song on the night of 7 August 1941, "sleepers" of the unnamed species awoke and began attacking everyone in sight. After leading them into the Torchwood Hub, Jack Harkness' singing of the song — which was, according to the Commodore pitch-perfect — made the aliens explode through sonic power, leaving nothing but pools of blood.
Its lyrics included: