If you would like to freely record instruments without having to predetermine the amount of bars in your sequence, please follow the steps below to disable the loop function...
1. Press the Main button
2. In the "Sequence" section, tap the button which displays an arrow running around in a circle, situated underneath "Start/End"
After following these steps, your sequence will begin with 2 bars, but as your live recording progresses to the end of the sequence, where it would normally repeat, it will simply continue to add bars until you stop recording.
As long as your hard drive doesn't fill up, you can add as many bars as you wish.