The History of The Beatles In Doctor Who
Perhaps no band in the real world has had quite as much of an impact on the world of Doctor Who as the Beatles did. Both were of course fantastic products of England in the '60s, but some of the connections go far deeper than a contemporary complementary pop-culture acknowledgment.
Doctor Who: Signs of Life
Almost every single incarnation of the Doctor has in some way participated in or manipulated the history of the Fab Four. In fact, there is at least one universe where the band was still active up to the Live Aid concert in 1985. A companion of the Eighth Doctor from his post-TV movie book series, Fitz Kreiner, made it a point to collect alternative timeline Beatles releases, and could play "Let it Be" on the piano.
Presumably that means he has a copy of "Colliding Circles" and "Left is Right (And Right is Wrong)."
More to the point, the Beatles were once supposed to appear in Doctor Who for the First Doctor story, "The Chase." Set in 1996, an elderly version of the band would have been still active and still performing at the Festival of Ghana in a brief cameo appearance.
Beatles manager Brian Epstein ultimately vetoed the idea, but footage of the band performing "Ticket to Ride" on Top of the Pops in 1965 is still featured in the first episode. Vicki refers to them as classical music. A museum in Liverpool is dedicated to them in her time, and they're still well-regarded enough as composers to be pub-quiz fodder in the 42nd century.
There is something very strange about that footage. It is the only surviving film of that Beatles appearance on Top of the Pops. All other copies have been lost. Considering that William Hartnell and Patrick Troughton's runs as the First and Second Doctors are rife with missing episodes junked by the BBC, it's very ironic that the show is responsible for preserving an otherwise lost piece of Beatles television history.
Actually it's double ironic, because licensing issues had necessitated the removal of the clip from all non-UK or Australian DVD releases.
Had The Beatles still been active in 1996, it would have of course been extremely anachronistic not only because of the band's breakup in 1970, but because of John Lennon's murder by Mark David Chapman in 1980. Even Lennon's tragic death has ties to The Doctor in Kate Orman's novel The Left-Handed Hummingbird.
In Aztec times, a warrior named Huitzilin was exposed to radiation from a crashed Exxilon spaceship. The energy enabled him to become the personification of Huitzilopochtli, a god of war and sacrifice that would feed on death.