Last week I told you about concert pianist Jonathan Biss' online course on Beethoven's piano sonatas, offered through Coursera in conjunction with the Curtis Institute of Music. The course has 25,000 participants, who log on weekly to hear one of the world's foremost pianists talk about one of the greatest composers of piano music the world has ever known. When I chatted with Biss about his course and his obsession with Beethoven, I asked him why he thought Beethoven's piano sonatas would make good material for an online course open to students from all around the world and from all backgrounds.  Hear his full response in the audio episode above. Check out Jonathan Biss' Coursera course, Exploring Beethoven's Piano Sonatas. Read more: Hey, Ludwig, There's an App for You (NYT)