To use the quantizer in Garageband:
- Select the track you want to quantize.
- Hit 'B' on your keyboard to bring up the Smart Controls.
- Choose the note value, ie, 1/16, on which you will base the time quantizer.
- Drag the “Strength” bar toward 100 to increase quantization.
How do you quantize in GarageBand IOS?
Quantize regions in the track
- Tap Track Settings, then tap Quantization. Quantization values appear in three categories: Straight, Triplet, and Swing.
- Tap one of the categories, then choose the note value you want to quantize the regions to.