On to the second operator. I’m going to add another sine wave, but on this one I’m going to change the frequency ratio to . So this sound will be 1 octave up from the first sine operator sound. Now I want to modulate the first operator with this, so on the modulation matrix I’m going to go to the second operator on the first line and increase the value slightly. Now you’ll hear how the one sine wave is modulating the other. You don’t need a huge amount to hear it. Subtlety is key here but the beauty is in the FM modulation of these sine waves. Extra harmonics get introduced and you get a more complex sound.