If our eyes only saw frames (IE: 30 images a second), like a single lens reflex camera, we'd see images pop in and out of existance and that would really be annoying and not as advantagous to us in our three dimensional space and bodies.
In the Vienna of the second half of the 18th century, in addition to Haydn and Mozart, three symphonic composers, namely Leopold Hoffmann, Carl Ditters von Dittersdorf and J.B. Vanhal helped further the development of the symphony.
The harmonica first appeared in Vienna, where harmonicas with chambers were sold before 1824 (see also Anton Reinlein and Anton Haeckl). Richter tuning, invented by Joseph Richter (who also is credited with inventing the blow and draw mechanism), was created in 1826 and was eventually adopted nearly universally.