How to Do AutoTune in GarageBand
The GarageBand audio recording application is part of the iLife suite that comes pre-installed on every new Mac computer. The application allows you to record digital instruments through the computer's input ports and non-digital instruments using the computer's built-in microphone. If you want to record your voice with the GarageBand application and apply an "auto-tune" effect to your voice, you can do so in a few simple steps.
Click the "Finder" icon in the computer's dock, followed by the "Applications" folder icon. Double-click the "GarageBand" application icon to launch the application.
Click the "New Project" option, followed by the "Voice" option. Click the "Choose" button to continue.
Type a name for the new project in the space labeled "Save As" and click the "Create" button to create the new project.
Click the "Male Basic" option if you are going to be recording a male's voice. Click the "Female Basic" option if you are going to be recording a female's voice.
Click the "Record" button to begin recording. Sing or speak into the computer's built-in microphone and the GarageBand application will capture your voice. When you are finished, click the "Record" button a second time to stop recording.
Click the "Audio Region" button in the bottom-left corner of the application window. Slide the "Enhanced Tuning" slider all the way to the right to the "100" position.
Place a check mark next to the "Limit to Key" option.