The Mad Hatter by Frank Wildhorn is in Em at 120 beats per minute and runs 4:35 across 115 bars. It uses 23 chords — Em(maj9), B7, N.C., Em, C7, Am7, B7sus4, Am, 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? The Mad Hatter guitar melody tab.