What specifically was Ludwig van Beethoven's ethnicity?

Answer 1

Although born in Germany, Beethoven's family originated from Flanders, which had been occupied by Spain for 200 years, with many Moors (North Africans). Contemporaries described the musical genius as having "thick, bristly coal-black hair," a "flat, thick nose," large mouth, and what is described as alternately a "ruddy" or "swarthy" complexion. In the middle of Teutonic Germany and Austria, he must have made a striking, memorable presence.

Beethoven's teacher, Haydn, was often called a "blackamoor." Alexander W. Thayer, one of the foremost authorities on Beethoven says, "Beethoven had even more of the Moor in his features than his master, 'Haydn.'" His features and family's Flanders heritage led him to be known as "the Black Spaniard."

(see http://www.mdcbowen.org/p2/sf/faq068.htm)

It's most likely he was mulatto, but DNA evidence was inconclusive. According to the Washington Post:

http://www.washingtonpost.com/ac2/wp-dyn/A25895-2000Oct17

The research team also said that future DNA analysis might answer lingering questions about Beethoven's ethnicity. As a young man, the dark-complexioned Beethoven sometimes was called "the Moor," and some historians have questioned whether he had African blood. Walsh said his analysis of the hair strands showed "no wrinkles or bends" typical among people of African descent, but that more tests may be conducted.

Answer 2

Ludwig van Beethoven born 16th December 1770, died 26th March 1827, was of German nationality.