Step 1: Launch project
We have here a GarageBand project containing a drum loop and a stack of four imported tracks, each containing a different take of the same backing vocal.
Step 2: I am the Groove Master
Hold the cursor over the left-hand edge of the drum track’s header, then click the star that appears in the rectangle to set that track as the Groove Master.
Step 3: Analyse this
A dialog box will appear, asking if you want to continue with the analysis of the audio within the project. Click Continue to begin the process.
Step 4: Follow tempo & pitch
A second dialog appears, asking if you want to enable the Follow Tempo & Pitch feature for the selected audio. This is necessary to make timing adjustments.
Step 5: Match Groove
Click the Match Groove checkbox in the header of the first track whose timing you want to correct. You should see the waveform shift slightly.
Step 6: Tick the boxes
Continue in this fashion for the remaining vocal tracks, ticking the boxes to ensure they are all in sync with the drums of your Groove Master track.
Step 7: Open audio editor
You can use Flex Time editing to quickly correct any anomalies. To begin, double-click the region where the error occurs to open the Audio Editor pane.
Step 8: Flex time
Click with the pointer in the upper half of the waveform display, and drag the problem note or beat to its correct length or position.
Step 9: Reset region
You can turn off Flex editing at any time for a specific region by clicking this button in the header of the region’s Audio Editor. This will restore its original timing.
Click the image below to zoom in and view the annotations.