Most of the time, it really is important to read the chart. Reading the charts fast enough to play along with them is a matter of learning what you're playing and practicing. I used to have problems with it but it eventually turns into reading the colors and their positions; it's just a matter of moving your fingers fast enough. Try using the lessons and minigames to help figure out the neck of your guitar so you don't have to look at it as you play, that might help.