See the complete series of Mastering Christmas Carols.
I Saw Three Ships: An Introduction
I Saw Three Ships is written and played here in the key of G Major, and has a 6/8 time signature. It could be written in 3/4 waltz time but having a six quaver measure length makes for simpler note values.
I Saw Three Ships: Main Melody
I Saw Three Ships is a very simple old English carol with two very similar sections. The lyrics are repeated in each verse, and the second line is always “On Christmas Day, On Christmas Day” while the fourth and final line is “On Christmas Day in the morning”.
Bars (measures) 1-5 contain the first phrase and 6-9 the second phrase. The notes are virtually identical except for the final bar and a bit with a rising then falling melody.
Here’s the complete melody written out:

And here’s what it sounds like:
I Saw Three Ships: Single Note Bass Line
Below is a simple bass line for the carol using just one note at a time.
Each note is a dotted quarter note (crotchet) meaning it takes half the bar. Only G and D are used throughout.

And here’s what it sounds like:
I Saw Three Ships: Adding Harmony And Fullness With Chords
In the third version of I Saw Three Ships, I’ve added primarily three-note chords to the right hand, always with the melody note as the highest note. The bass line remains the same.

And here’s what is sounds like:
See the full range of Christmas carol lessons we’ve published.