This toy is very open-ended. You specify a series of transformations on a musical phrase. The initial musical phrase, on which the transformations are performed, is obtained by taking the letters of a word (the initial word is "init"). The transformations are then applied in sequence, one after another. Initially there are no transformations in the list - you should specify a new transformation and then add it to your list. Every time you add a transformation (or edit an existing transformation), the entire chain will be re-evaluated, and the MIDI phrase (shown in piano-roll format) at the top of the page will show the new result. There is a large selection of transformations to choose from. Using this one requires imagination and experimentation, but the results can be quite interesting. This one gives you a little flavor of the things you can do, algorithmically, with KeyKit.

A Few Hints . . .

Choose transformations like 'Echo' to add more notes
Use the Pick control to randomly select the notes to affect.
You can modify (and delete) transformations in the list of transformations you've already added.