The melody of The Christmas Song (Chestnuts Roasting On An Open Fire) by Mel Torme runs 220 notes across 45 bars, 2:21 long in Gb at 80 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? The Christmas Song (Chestnuts Roasting On An Open Fire) chords and lyrics.