By Paul McGowan From PS Audio

I fell in love with musical synthesizers at an Emerson Lake and Palmer concert in Munich, June, 1971. The venue was called Cirkus Krone, a theater in the round, and seated high above the stage, I witnessed an extraordinary event in rock and roll history. Keith Emerson stood in front of the most magnificent machine I had ever seen. Wires sprouted like weeds, lights flashed, sounds soared in ways I had never heard. Here’s a picture of what that looked like.

If you go to: https://www.youtube.com/watch?v=MRYx0ySEhjk you can get a taste of what I experienced that night. Though this YouTube video is rather tame compared to what I remember of soaring swoops, glides, and never-before-heard intensities – in full surround sound – the music that night reverberated throughout Cirkus Krone and eventually the whole world. So new was this sound it started a stampede of German fans trying to rush the stage, to touch the machine, to be a part of history being made, and they were held back with great effort by nearly overwhelmed security. None attending that night had ever witnessed anything like it, and perhaps none have since.

I had been smitten by the Moog bug and on that very night in June decided I would make it my business to learn how this electronic beast worked. I just had to know.

I studied every piece of literature available at the time, but much of the workings of a Moog synthesizer were shrouded in mystery and little technical information was available. That remained the situation until a few years later when I met Giorgio Moroder, a meeting I have chronicled in these pages before. Moroder had a synthesizer and while not technical enough to help me understand its workings, his engineer, Reinhold Mack was the first fountain of knowledge I came across.

It was Mack who explained to me the idea of voltage controlled components that made the Moog work. And he told me that essentially there were only a few key components I need understand, all voltage controlled: an oscillator to make the sound, a keyboard to select the voltage, a filter to change the character, and an amplifier to form notes. And while there were other elements like envelope generators, klangers, ring modulators, control oscillators, ribbon band controllers, and mixers, none played more important roles than the four basics mentioned.

There was one downside that intrigued me: only one note could be played at a time. Because the keyboard is a voltage divider each note pressed outputs a single voltage which is eventually turned into sound. If you press two keys you don’t get two voltages. Musicians could not play complex chords using multiple keys, as with a piano.

That limitation set me on the road to a new idea.

For more on this story go to: http://www.psaudio.com/pauls-posts/elp-concert/