You can loop regions so that they play repeatedly, and extend them to fill any amount of musical time in the Tracks area. When you play the project, the region repeats the number of times you have extended (looped) it.
You can also loop a region that has been resized. When you loop a resized region, only the visible portion of the region repeats when you play the project. If you add silence by lengthening a region, the silence is included in each repetition when you loop it.
In GarageBand on Mac, place the pointer over the upper-right edge of the region.
The pointer becomes a Loop pointer.
Drag the right edge of the region until it aligns with the point where you want it to stop playing.
As you drag the edge of the region, “notches” appear at the top and bottom of the region, showing the beginning and end of each complete repetition.
In GarageBand on Mac, control-click the region, then choose Loop On/Off from the shortcut menu.
The region loops repeatedly until the end of the project.
To unloop the region, control-click the region, then choose Loop On/Off from the shortcut menu again.
