The melody of Have Yourself A Merry Little Christmas by Sam Smith runs 184 notes across 39 bars, 2:35 long in Bb at 65 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? Have Yourself A Merry Little Christmas chords and lyrics.