LETTERS OF NOTE: Keller and Beethoven

Today's Letter of Note has a musical feel to it - with pun firmly intended on this occasion, concerning as it does the blind and deaf author Helen Keller and the way in which she responded to the music of Ludwig van Beethoven.
On February 1st 1924, the New York Symphony Orchestra played Beethoven's Ninth Symphony, a piece later immortalised by Stanley Kubrick in  A Clockwork Orange. The performance was broadcast live over the radio, and one of those tuning in was American author and activist Helen Keller, who was famously deaf and blind from a very young age. Two days later, the NYSO received a letter from Keller, describing how she had 'heard' the concert by holding her hand against the speakers and picking up the vibrations.
Keller's extraordinary and awe-inspiring letter can be read in full here. Its timing is all the more extraordinary for me, since tomorrow marks the opening night of Two Fat Men. Late in the play, my character bonds with a deaf lady who can feel his dancing vibrations through the floor; they strike up a friendship, and we are left with the suggestion that it may turn into something more.
One might also suggest, on a more tragic note, that Keller probably heard more of the Ninth Symphony in this instance than Beethoven ever did. At the piece's premiere in 1824, one hundred years before the radio broadcast, he had to be turned around by the contralto to view the standing ovation he was getting. Being completely deaf at this point, he couldn't hear a note that was being played.