The Beethoven Portrait is modeled after the actual Beethoven, having fair skin, long curly gray hair and a cleft chin. He wears a black open tail coat over a yellow waist coat, a white bowtie, gray pantaloons and a pair of brown shoes.
Not much is known about the Beethoven Portrait's personality other than that he is a bit mischievous as he plays the piano to prank the humans of the school.
The Beethoven Portrait appeared in the episode ten of the sixth anime, Vanishing! The Seven School Mysteries. He along with the other seven mysteries are captured and were hung up in the gymnasium by Yōsuke-kun, when he believed that they were after Hanako-san. After Yōsuke was defeated, he is rescued and returns back to his piano room.
Portrait Exiting: Mana mentions that he is capable of exiting his portrait to play the piano.
Pianist: He has knowledge and the proficiency to play the piano.
While mentions of Beethoven playing the piano are not as common, there are urban legends with the piano that is said to play on its own at night.