The orange letters show the actual notes, while the red letters are the keys that you press to get those notes. This is a two octave A Minor scale. Use the red boxes in the upper keyboard to play different beats. Use the up and down arrow keys to adjust the tempo. Click on the different colored boxes for different beats. Use z, x, c, v, b, n, and m to change to a different instrument.
DO NOT TRY CLICKING ON-SCREEN KEYS! USE YOUR COMPUTER KEYBOARD KEYS! THE ON-SCREEN KEYS ARE FOR REFERRENCE PURPOSES ONLY! THE ONLY FEATURE THAT IS CLICKABLE IS THE COLOR-CODED SQUARES FOR THE BEATS. Thanks to LopezReyesD2531 for the picture.
