This is what Home Concert might look like in Notation View on a Mac (Windows would be virtually identical) while the performer is playing in bar 17 of Beethoven's Ecossaise. Notice that the current measure is highlighted in gray. Since the performer is getting toward the bottom of the page, Home Concert has started to "turn" the page. It does that by scrolling the gray bar down the page, revealing as it goes the top of the next page. When the performer gets to the next page, the gray bar disappears to the bottom, and new page is displayed in its entirety.

And, of course, while the soloist is playing, Home Concert is playing the programmed accompaniment for this piece, synchronized to the performance.