Enter The Circus by Christina Aguilera is in Am at 160 beats per minute and runs 1:44 across 19 bars. It uses 5 chords — Am, Ab, G#+, Bm, A#+. The chord diagram changes as the song plays and the words light up as they are sung, so you can strum and sing along without reading ahead.
Want the melody line note by note? Enter The Circus guitar melody tab.