My arrangement of this famous Christmas carol tune is based on anonymous four-part harmonies for tin whistle quartet that I found on a Japanese web site. I have distributed these harmonies onto a romantic mandolin quartet instrumentation, for two mandolins, octave mandolin/mandola and tenor guitar. I start on only the guitar and octave mandolin, with the mandolins building up harmonies when they come in one by one.

Mid-Missouri M-0W mandolin
Gibson Ajr mandolin
Ozark tenor guitar
Mid-Missouri M-111 octave mandolin