The soprano sings the melody; the other three voices are auto-harmonized underneath in diatonic thirds — a hymn/chorale texture. Transposed by Root.
Singers
Each column is a singer. Drag a blob up/down to change its pitch — it snaps to the scale, so the four voices always sound good together. Drag left/right to morph the vowel (ooo → ahh → eee) via real formant synthesis. Flip on Auto-choir and just listen.