"Moonlight Serenade"
"Moonlight Serenade" was a song by Glenn Miller.
DJ played it when he met Peri in Tranquil Repose. (TV: Revelation of the Daleks [+]Loading...["Revelation of the Daleks (TV story)"])
Jack Harkness played while he was discussing "business" with Rose Tyler, whom he believed to be a Time Agent. (TV: The Empty Child) He later played the song on a radio via his Chula warship's Om-Com for the benefit of Rose and the Ninth Doctor, who were trapped in a storeroom in Albion Hospital, so Jamie couldn't find them. Rose attempted to dance to "Moonlight Serenade" with the Doctor. The Doctor later had "Moonlight Serenade" playing in his TARDIS console room when he rescued Jack Harkness from the destruction of the Chula ship. (TV: The Doctor Dances [+]Loading...["The Doctor Dances (TV story)"])
Behind the scenes
In the real world, "Moonlight Serenade" was released in 1943, two years after the setting of The Empty Child.