Hi there! Every music symbol is now related to a specific black key. As you have learned within the first song, squares and rectangles always refer to black keys regardless of wether they are white or black. Black squares are quarter notes on the black keys and white rectangles are half notes or dotted half notes on the black keys. Some songs further on there will be introduced circles and ellipses which will represent the white keys.
The animation with the colored keys and the green moving song position line will not be part of the iOS app because this will distract the student form reading the music.
New version of the demo clip of piece no. 2 “Waltz of the Bear”