It is a special mode, aimed at simplifying the process of playing an instrument and learning new scores.
In this mode, users see scores in a "continuous view" shown in one line with perfect readable scaling applied. Simply by tapping the piano icon button, users hear the metronome intro which is followed by the convenient flow of notes. Users can always see what they’re playing, along with a couple of more measures that are coming up next.
On the same screen, users not only change the tempo, the key, or turn the metronome on/off but also play the original sound of the instrument (to hear whether they’re playing it correctly), rewind score, and change tempo.