GarageBand for iOS 1.4 or later: How to turn off "Snap to Grid"
"Snap to Grid" can be turned off to get finer control over region and note editing.
To turn off "Snap to Grid," pinch-zoom to the maximum level in Tracks view or when editing notes in regions. Pinch-zoom again and "Snap to Grid off" will appear on top of the Tracks area.
To turn "Snap to Grid" back on, pinch-zoom out.