Ableton's Shape Generator is used here to build a counter-melody on a separate MIDI track, with the full parameter set walked through in a compact, practical demo. Pitch range is set first using the Minimum and Maximum Pitch choosers, placing the generated melody in a slightly lower register than the main idea.
The Rate knob controls the minimum note length and defaults to the current grid, while the Tie knob sets the probability that a note extends and merges with the one that follows. Density determines how many notes are generated within the chosen shape, and Jitter introduces random deviation to keep the pattern from feeling too mechanical.
Beyond the built-in presets available in the dropdown, you can draw entirely custom melodic shapes, which is where the tool becomes genuinely flexible. Combining these parameters gives you a fast way to sketch counter-melodic ideas that can be refined or randomized further from there.