The Arrange window channel strip sits in the bottom left corner of the Arrange window. It looks like a software emulation of the channel strip you'd see on a classic analog mixing console. The Arrange window channel strip always updates to display the channel strip for the track currently selected in the Arrange window's Track List. This makes it easy to both arrange and mix your songs right in the Arrange window.
Viewing the Arrange Window Channel Strip
The channel strip is big, and it takes up a significant portion of the Arrange window's left edge. In fact, in the song you're looking at, the Region Parameter box, toolbox, Object Parameter box, and channel strip are all fighting for real estate. By default, the top of the channel strip is hidden so you can see the other display boxes. To see more of the channel strip you can either stretch the Arrange window vertically to make it taller, or use the following trick.