How do I put a certain fragment of the song on repeat?

I have an issue with repeating a certain fragment of a song in the latest GarageBand on iPhone.

You can loop and repeat regions, but not parts of a song, meaning looping all tracks in parallel.

if you want to repeat a part of a region in a track, split the region eat the beginning of the section you want to repeat, and at the end of this section.

http://help.apple.com/garageband/iphone/2.1/index.html#/chsec12c15d

• Tap the region to select it.
• Tap the region again, then tap Split.
• Drag the Split marker (with the scissors icon) left or right to the point where you want to split the region.
• Drag the Split marker down.To cancel the split, tap anywhere outside the region before dragging the Split marker down.
• To make multiple splits, move the Split marker to different parts of a region and drag it down in each part.

Then loop the cut out region:

• Tap the region to select it.
• Tap the region again, then tap Loop.The region loops until the end of the song section, or until the beginning of the next region in the same track. You can change how long it loops by dragging the right edge of the region.