O Holy Night by Glee Cast is in A at 75 beats per minute and runs 4:48 across 36 bars. It uses 10 chords — A, D, E7, C#m, G#7, E, F#m, Bm, 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? O Holy Night guitar melody tab.