If you tap a Main button twice rapidly, the Main will change WITHOUT playing a fill in.
When playing in the ACMP mode AND using Fingered 1 or 2 fingering, a break can be made by pressing any THREE close notes (e.g. F, F# and G) at the left side of the split point.
Now only the drum channels will be playing until you play a chord with your left hand.
When playing in the ACMP mode AND using Fingered 1 or 2 fingering, a break can be made by pressing any FOUR close notes (e.g. E, F, F# and G) at the left side of the split point.
Now only the drum and the bass channels will be playing until you play a chord with your left hand.
The bass channel will play its pattern with the lowest note of the four notes pressed as the root note. In the example above the bass pattern will be played with E as root.