In November of 1906, Lee de Forest, adapted a Fleming valve by adding a wire grid between the bulb's filament and plate. The grid allowed the regulation of the flow of electrons between the filament and the plate, thus turning the tube into an amplifier. However, de Forest never did fully understand how or why it worked. As well, de Forest was frequently the subject of patent infringement cases and other litigation. He was referred to as the "father of radio" but his contribution to radio was like that of a father in the biological sense; he briefly performed a function, and then left the real work to others.
See: http://invent.org/book/book-text/30.html
On Christmas Eve 1906, radio listeners near Brant Rock Massachusetts were startled to hear first a woman sinning, next, someone reading a poem, and later, Reginald Aubrey Fessenden playing "O Holy Night " on the violin. This was not only the first transmission that was not all code, but it was also the first radio broadcast in the sense of "widely scattered." Prior to that night, all radio broadcasts were intended to be point to point, from a single sender to a particular receiver. One could listen in to such transmissions, but their content was usually for the benefit and use of the sender and intended receiver.
See http://www.icce.rug.nl/~soundscapes/VOLUME02/Reginald_Aubrey_Fessenden.html