I was attracted to this song because of its simple beauty. In this instance, it was challenging to preserve the natural characteristics of the song yet create interesting variations.
I started first with an unaccompanied version of the song played by tuba alone. I found the motif of the last two measures to be the most interesting part of the song and used it to create an ostinato in the next section. The right hand of the piano plays simple arpeggiated chords. I move the tuba to the upper register as I love the sonority of the instrument in that range.
At measure 19, the key changes, the tempo increases slightly, and the melody and accompaniment are more elaborate. I trade the melodic phrases between the tuba and piano. I also add some borrowed chords, one at measure 24 and the others at measure 27. The ones at 27 create a deceptive cadence and a modulation back to the original key.
Measure 28 ushers in the most elaborate setting of the song with chromatic lines in the piano left hand switching to the right hand 4 measures later. The tuba is once again in its high register. The key change at measure 37 has the piano playing the tune in canon while the tuba plays an obligato. The movement ends with chromatically altered chords over my favorite motif.
Below is a video of the score that uses sampled sounds. Your comments are always appreciated.