The material of the book itslef is great. I’ve been using this series for two decades of piano instruction. I was excited to try the electronic version and was considering recommending it to my students as well. There is one frustrating glitch that is annoying enough to deduct two stars from my rating. When you click on the icon to make the page full-size, it rotates it so the page is landscape, while the material is still portrait. In other words you have to bend your head fully to the right in order to view the page correctly! It’s a relatively simple fix; I just take a screen shot and rotate the image 90 degrees to the left. However though siimple, this is a step I shouldn’t have to take for *every piece in the book*. I also cannot ask my students to have to do so either. Fix this issue and I’ll gladly bump my rating to a full 5 stars.