29 in by 21 in
Einstein once said that had he not been a scientist, he would have been a musician. “Life without playing music is inconceivable for me,” he declared. “I live my daydreams in music. I see my life in terms of music…I get most joy in life out of music.” He never went anywhere without his violin, named Lina. He particularly loved to play Mozart Sonatas and Quartets, often playing the quartets with other scientists and professors who also played music.
Einstein credited his violin playing experiences with leading to some of his greatest insights. Einstein explained that he loved Mozart because it seemed that Mozart was capturing a pure music that was simply formed by the universe or divined by God. Mozart himself would sometimes say that he felt like he was not composing so much as taking dictation.
This makes sense though. Einstein never saw himself as creating anything. His quest was to simply discover how the universe worked, perhaps to explain it. Mozart and Bach had a structure and simplicity that he saw as coming naturally from the universe, not from Mozart or Bach themselves. It fits with his life long quest to explain the physical universe in a complete and organized way.