Please follow these instructions to control Auto-Tune Pro or Auto-Tune Artist's pitch correction with a MIDI track in Logic Pro X:
1. If you intend to use a MIDI keyboard, connect it to your computer, start Logic Pro, and make a new session.
2. Create an audio track and software instrument track. Record or import an audio recording onto the audio track.
3. Set the output of the audio track to "No Output."
4. Load Auto-Tune Pro (or Auto-Tune Artist) as the "Instrument" input on the software instrument track. (It's available under: AU MIDI-controlled Effects > Antares)
5. In the Auto-Tune plug-in window, click on the "Side Chain" drop-down menu in the upper right corner and select the audio track you created in step 2 (for example, "Audio 1").
6. Click on the "Advanced" view button and then the "Target Notes" MIDI button to enable MIDI note control of Auto-Tune's target pitches.
7. Select the software instrument track and click on the red "R" button to record enable it.
8. Start playback (or recording) and perform on your MIDI controller to pitch correct your audio recording in real time. Alternatively, you can import a MIDI file onto your software instrument track and use this instead.