Bad Day by Daniel Powter is in Ab at 140 beats per minute and runs 3:19 across 89 bars. It uses 19 chords — N.C., Cm, Eb, Ab, Fm7, Bb, Bbsus2, Ab6, and a few more. 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? Bad Day guitar melody tab.