"Calling" is the closing theme of Final Fantasy VII: Advent Children. It plays during the second part of the credits, which depict Cloud riding along a highway in the countryside, as he makes his deliveries and heads towards home. Although the Cloud in the sequences is CGI, the background shots of the sequence are real world footage of Hawaii.
"Calling" was actually written in 1989, as part of the album Neo Fascio by Kyosuke Himuro, who wrote and sung the piece. In 2005, it was used as Advent Children's theme in the closing credits, and Himuro has stated he was honored to have his work included in the film. For the remake of Advent Children, Final Fantasy VII: Advent Children Complete, he wrote a new song "Safe and Sound" with Gerard Way, though the theme was only used in the Japanese version's ending.