Structure free is an instrument plug-in that does not require a midi controller to function. The default setting is a sine wave patch. To load a patch, click on the browser tab – application-digidesign-protools creative collection/Structure free. There are 6 smart knobs and a master fader. There are factory pre-assigned, useful parameters. There is Chorus Mix, Reverb Mix, Cutoff (applies an EQ filter), Resonance (controls the resonance of the cutoff), Attack, Release, and Master control. There are green keys that can loop patches and creates a variation of the groove and blue keys. These key switches are velocity sensitive. You can change the pitch and tempo of the drum kits. Key switches do not produce pitch, they send info. The keys are green when used, and blue when not used. Key switches produce a variation in the loop of the patch. Pull up a loop, note where the key switches are, play them play with your left hand while you use switch keys with your right while recording. Bring up the midi edit window, and pull the key switches out of their range and they will become pitches. The patch module contains the patch list. You can create, midi assign, mix, select, route, and group patches. By clicking on patch, you have the option to load a new patch, add a patch, duplicate, remove one or all patches.