The latest Google Doodle is on its way to becoming one of the most popular to date, equal to the Les Paul guitar one. But, just like the guitar doodle, the Moog synth doodle is more complex than it looks. The multitude of unlabeled knobs will put off most people and just randomly playing with the buttons is not going to help you much, especially if you have no idea of how a synth is supposed to work, even more so an old-school one like the Moog.
Luckily, both Google and the Moog company have created handy guides explaining all the buttons and their functions. To the left, you'll find the Mixer section with a master volume knob and then individual volume buttons for each oscillator.
In the Oscillator function, you'll be able to select the Range, Waveform and, for two oscillators, the Frequency. The Filter section enables you to control the cutoff frequency and color the sound with Pitch Glide and Contour. You also get ADS controls for the filter and finally, for the entire synth in the Envelope section.