"Song for Four"
From Tardis Wiki, the free Doctor Who reference
"Song for Four (Home)" was a musical piece composed by Murray Gold.
It was originally intended to be used for the reveal of the Curator, as well as the Eleventh Doctor's monologue, during the final moments of the 50th anniversary special The Day of the Doctor. In the final cut, however, it was replaced with a version of the Series 6 track "The Wedding of River Song".
The piece was eventually used in the first episode of Series 8, Deep Breath, during the Eleventh Doctor's phone call to Clara.
The piece is featured on Murray Gold's soundtrack Doctor Who - The Day of the Doctor / The Time of the Doctor.