When playing the songs some of the notes will be shaped like stars, these are star notes. If you play all the star notes with no mistakes, on the last note a blue spark will appear. This gives you star points and the microphone meter fills up a little on the touch screen. If the last star note is a long note, the longer you hold it out the more the meter will fill up. When the words appear on the screen "Star-Meter Full" yell, or blow in the microphone. You could also push select or tap on the microphone meter on the tap screen. When you do this all notes will turn blue and your character wwill start dancing. While in the star zone, your multiplier will stay the same.