Lee De Forest , The self styled “Father Of Radio” ( the title of his 1950 autobiography) inventor and holder of over 300 patents, invented the triode electronic valve or ‘Audion valve’ in 1906- a much more sensitive development of John A. Fleming’s diode valve. The immediate application of De Forest’s triode valve was in the emerging radio technology of which De Forest was a tenacious promoter. De Forest also discovered that the valve was capable of creating audible sounds using the “heterodyning”/beat frequency technique: a way of creating sounds by combining two high frequency signals to create a composite lower frequency within audible range and in so doing inadvertently invented the first true audio oscillator that paved he way for future electronic instruments and music.
“Sounds resembling a violin, Cello, Woodwind, muted brass and other sounds resembling nothing ever heard from an orchestra or by the human ear up to that time – of the sort now often heard in nerve racking maniacal cacophonies of a lunatic swing band. Such tones led me to dub my new instrument the ‘Squawk-a-phone’….The Pitch of the notes is very easily regulated by changing the capacity or the inductance in the circuits, which can be easily effected by a sliding contact or simply by turning the knob of a condenser. In fact, the pitch of the notes can be changed by merely putting the finger on certain parts of the circuit. In this way very weird and beautiful effects can easily be obtained.”
(Lee De Forest’s Autobiography “The Father Of Radio”)
And From a 1915 news story on a concert held for the National Electric Light Association
“Not only does de Forest detect with the Audion musical sounds silently sent by wireless from great distances,but he creates the music of a flute, a violin or the singing of a bird by pressing button. The tune quality and the intensity are regulated by the resistors and by induction coils…You have doubtless heard the peculiar, plaintive notes of the Hawaiian ukulele, produced by the players sliding their ﬁngers along the strings after they have been put in vibration. Now, this same effect,which can be weirdly pleasing when skilfully made, can he obtained with the musical Audion.”
“De Forest has said in many newspapers and over his signature that it would be possible to transmit human voice across the Atlantic before many years. Based on these absurd and deliberately misleading statements, the misguided public … has been persuaded to purchase stock in his company. “
De Forest collaborated with a sceptical Thadeus Cahill in broadcasting early concerts of the Telharmonium using his radio transmitters (1907). Cahill’s insistence on using the telephone wire network to broadcast his electronic music was a major factor in the demise of the Telharmonium. Vacuum tube technology was to dominate electronic instrument design until the invention of transistors in the 1960′s. The Triode amplifier also freed electronic instruments from having to use the telephone system as a means of amplifying the signal.