Adding piano dynamics
Adding dynamics so the program judges where you are playing crescendo, p, pp, mp, mf, f, and so on.
Gina Soth commented
This is more for piano, but as I came from traditional lessons, musical elements such as articulation, tempo and dynamics are essential in learning how to be a musician. This is especially important when someone has no formal music education at all. Having theory videos and having indicators when playing would be extremely beneficial.