Ludwig van Beethoven

Ludwig van Beethoven was a German composer.

The Sixth Doctor was present at the birth of Beethoven and gave his mother enough money to raise the child that her husband did not want. (PROSE: Gone Too Soon)

The Tenth Doctor claimed to have learned how to play the organ (or possibly keyboard instruments in general) from Beethoven, suggesting the two had met. (TV: The Lazarus Experiment) After the Doctor and Beethoven were abducted by Momus for a dinner party, the Doctor told Beethoven that he loved his Fifth. (WC: The Lonely Computer)

In an incident at the Royal Albert Hall, the Tenth Doctor claimed to have once asked Beethoven if he could "rattle off a tune," to which Beethoven reportedly replied, "Pardon?" (TV: Music of the Spheres)

On Nocturne, Korbin Thessinger played Beethoven to lure a noise creature into a trap. (AUDIO: Nocturne)

When the TARDIS landed in the Hanging Gardens of Babylon, the First Doctor said that the music they were hearing was not Beethoven. (AUDIO: Farewell, Great Macedon)

Beethoven wrote "Ode to Joy", which was part of Beethoven's Ninth. (PROSE: Ode to Joy)

The Twelfth Doctor used the hypothetical non-existence of Beethoven in a story (which didn't happen) as an example of the "Bootstrap paradox", where a time traveller travelled back to 18th century Germany and copied out the concertos and symphonies he had brought with him and got them published after finding out no-one knew who Beethoven was, the time traveller essentially becoming Beethoven. He described Beethoven as a "[n]ice chap, very intense," and that he "[l]oved an arm wrestle." (TV: Before the Flood)

Behind the scenes
Beethoven was played by Paul Rhys in the BBC miniseries Beethoven.