All I Want For Christmas Is You by Mariah Carey is in G at 120 beats per minute and runs 3:24 across 64 bars. It uses 11 chords — G, Em, C, D, Cm6, Baug7, E7, Am7, 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? All I Want For Christmas Is You guitar melody tab.