The melody of O Holy Night by Glee Cast runs 234 notes across 36 bars, 4:48 long in A at 75 beats per minute. The tab sits low on the neck, mostly under the fourth fret, one note at a time — no chords to barre and no strumming pattern to keep up with. A piano backing track plays the chords and bass underneath, so the line you are learning sounds like the record even at half speed.
Prefer to strum and sing it instead? O Holy Night chords and lyrics.