ABBA

ABBA were a Swedish band popular during at least the 1970s.

The Tenth Doctor used his psychic paper at an ABBA concert to convince security that he and Donna Noble were Björn and Frida, two members of the band itself. (AUDIO: Dead Air)

When Ace was nine years old, she was given an ABBA record as a reward for being a brave girl when she went to the dentist. (PROSE: Tragedy Day)

Melanie Bush liked ABBA in her youth. (PROSE: Business Unusual)

In college, Gwen Cooper found out a number of her boyfriends were interested in ABBA and other men. Connecting the two, she was thankful that Rhys Williams never liked the band. Conversely, Ianto Jones liked their music in general but hated the song "Dancing Queen". (PROSE: The Twilight Streets)

Jack Harkness remembered them winning the Eurovision Song Contest. (AUDIO: The Dead Line)

The Sixth Doctor's companion Flip Jackson never possessed a solid grasp of history and her only knowledge of the Battle of Waterloo on 18 June 1815 came from ABBA's song "Waterloo". Upon meeting Napoléon Bonaparte only hours before the battle was to take place, she told him of its outcome by quoting the song's opening lyric: "At Waterloo, Napoléon did surrender." (AUDIO: The Curse of Davros)

Behind the scenes

 * Two members of ABBA were interested in producing a musical based on Torchwood.
 * In the video game, NOTDWU: Attack of the Graske, the Tenth Doctor explained to the player Rose Tyler's absence from the game was due to her going to a 1979 ABBA concert in Wembley. Due to issues arising from the seeming fourth wall break from the Doctor talking to a player that has been watching his adventures, as well as the game having multiple endings to choose from, this wiki does not consider Graske a valid DWU source.