It does not hurt to play a simple carol in a beautiful and calm way. You feel strangely moved (it’s the open chords).
Apologies to the King of Rock and Roll! The triplets are tricky. See also my Queen’s Crazy Little Thing Called Love for bass line technique. Practise bass (left hand) first before attempting melody.
Just for fun, I am showing you how to give a classic tune a jazzy sound. You have to use chord substitutions. You can turn any song into a jazzy number. Even the Ramones at a pinch.