After you've applied Pitch Automation to a track in Digital Performer 4.6, you can edit, erase, or disable your pitch correction changes a number of different ways. First, of course, is Undo. With DP's virtually unlimited Undo history, you can effectively step backwards through your edits or dive into the Undo History to select a single edit.

Second, you can erase a range of pitch automation moves. In the Sequence editor, select "Pitch" as the active layer, and then click and drag over the range you wish to eliminate. Then simply hit the "Delete" key. Your track will return to its unaltered state.

Finally, you can disable Pitch Automation on a track-by-track basis. Again with "Pitch" as the active layer in the Sequence editor, note that there's a tiny "P" button beneath the pitch ruler. Click it (it turns white) and pitch changes will be disabled until you click the box again.