ShakePad (Mac/Win, $30 approx.) is an AU and VST effects plug-in designed for hands-on control. It features 50 stereo effects presets and a prominent xy-controller to manipulate two parameters for the chosen preset. You can work the controller with your mouse or assign it to a pair of MIDI controllers or to a 2-D MIDI joystick or pad. In addition, you get Wet/Dry and Release sliders and a Hold button. When Hold is on, the xy-controller stays where you leave it; otherwise, it drifts back to the lower-left corner (bypass) or to any location you specify by right-clicking with the mouse. The rate of drift is set by the Release slider.
The 50 effects are well chosen for this type of control. You get lots of filters and time-based effects (phasers, flangers, delay, echo and loopback). You'll also find variations on distortion, panning and gating. Many of the presets pair an effect with either delay or phasing. And for good measure, there are a few effects that generate sound on their own — Theremin, warbling oscillators, siren and a chanting voice. With a little automation or great digital dexterity, you can make the chant accompany your melody (see Web Clip 1).
The various flavors of distortion, especially coupled with delay, work well with percussion. For those, the snap-back feature (Hold off) comes in handy. Set up MIDI control of the Release slider, then click and release anywhere in the xy-controller graphic and change the release time for each click (see Web Clip 2). Also try different return locations.
Of course, you're not limited to one instance of ShakePad. Web Clip 3 uses eighth-note-triplet gating followed by steep resonant-lowpass filtering. You can purchase ShakePad or download a noise-spewing demo from the Genuine Soundware Website (genuinesoundware.com). It's well-worth checking out.