Acoustic instruments are inherently complex, and great instrumentalists know how to capitalize on this tonal complexity to achieve affecting performances that reinforce the emotional message of a song. The tamed chaos of acoustic instrumentation is part of what makes it so interesting. No two notes are ever the same and instruments sound different across their registers- producing sonically appealing variation that is musically logical. A great example is the human voice- if a singer wants a particular passage to be especially impactful, they can strain against the edges of their register producing timbres that agree with and reinforce the message of their song. In contrast, synths, especially digital ones, can seem a bit sterile- which can lead to fatigue and loss of interest on the part of a listener accustomed to more variety. There are many techniques to combat this, a favorite of mine is to design synth patches that vary in tone and timbre across the keyboard by using Keytracking, which is the modulation of synth parameters by the pitch position of the notes played. There are many possible modulation targets, but in this example I will be using Ableton’s Expression Control Max for Live plugin (Categories>Max for Live>Max Midi Effects) to modulate the Wavetable position of Ableton’s new Wavetable synth. By assigning Keytracking to modulate the oscillator’s position in a Wavetable that trends from low to high harmonic complexity, we will be able to model some of the harmonic changes that take place as acoustic instruments move up and down their register. For simplicity we picked Wavetable preset “A Soft Chord.” Which uses the Basic Shapes Wavetable which morphs through the four main Wavetypes: sine-triangle-saw-square. This is ideal, because sine and triangle waves produce gentle harmonics, while saw and square waves have rich harmonic profiles. The image below shows how to map the Keytracking parameter (if you’re on mobile-pinch to zoom! All images are high resolution):