"Love Don't Roam" was a song playing at what would have been the wedding reception of Donna Noble and Lance Bennett, had they actually gotten married. Though most of the wedding guests were dancing vigorously to the song, the Tenth Doctor leaned up against the bar and investigated the ownership of H.C. Clements on a stranger's cellphone. Then, as he began to actually listen to the lyrics of the song, which referenced a loved one vanishing, the Doctor caught a glimpse of a blonde woman on the dance floor who reminded him of the recently-lost Rose Tyler and began to have short flashbacks of his time with her. Quickly dismissing the emotion of the moment, he noticed the wedding photographer and began to investigate his recording of Donna's earlier disappearance during her wedding. The song continued to play until the Santaroboforms began to attack to the reception hall. (TV: The Runaway Bride)
"Love Don't Roam" was the second original song commissioned for the revived Doctor Who series, and the first to appear diegetically — that is, in such a way that the characters were shown to be hearing it. Unlike the earlier "Song for Ten", then, it was not incidental music, but instead an actual part of the narrative.
One line of the song (heard on the soundtrack album, but not in The Runaway Bride) included the words, "all the strange, strange creatures." This would later be used by Gold as the title for his secondary theme composition, which would also be known as the "trailer theme" for its frequent use in trailers. Thus although the series 3 soundtrack album does not include "Love Don't Roam", it does include an instrumental piece named by a lyric within "Love Don't Roam".