The melody of I Believe In Father Christmas by Greg Lake runs 144 notes across 15 bars, 2:11 long in D at 116 beats per minute. The tab sits almost entirely in the first two frets, 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? I Believe In Father Christmas chords and lyrics.