Gary Oldman actually played all of the Beethoven pieces he performed in the film. A different musician performed in the official soundtrack. When Oldman learned he would be playing the lead role, he spent six weeks practicing on a Steinway piano for six hours a day in his hotel, and completely immersed himself in the music as his research for the character. In an interview with the South Bank show in 1997, Oldman quoted an article that said "he mimes very well" in the film. He then laughed and said "I'm playing it! I can play that!"
In real life, Schindler was not a close friend of Beethoven, though he was Beethoven's secretary for a while. It has been claimed that Schindler destroyed 260 of Beethoven's approximately 400 conversation notebooks, although this belief has been challenged in recent years, and forged entries into the surviving ones. Beethoven's actual eulogy was written by poet Franz Grillparzer and given by actor Heinrich Anschütz.
Bernard Rose removed the music from the Columbia and Focus opening segments. He thought they sounded "cheesy" compared to Beethoven.
Beethoven's remarks to Schindler during their first meeting, at a rehearsal of the Kreutzer sonata, is taken from Tolstoy's short story "The Kreutzer Sonata".
Beethoven wrote a love letter to his "Immortal Beloved" in the summer of 1812, at the spa in Teplitz. Her identity has long been a subject of debate. Possible candidates include: Julie Guicciardi, Therese Malfatti, Josephine Brunsvik, and Antonie Brentano.