Did these last night; we’ll see how they turn out for their corresponding students, since I typically write my arrangements from start to finish without sound and without playing them on any keyboard. There’s no magic to acquiring the perfect mental pitch reproduction that allows correspondingly fast writing—just lots of repetition and practice with increasingly self-reduced access to a perfect pitch authority (such as a piano, that is) over months and years.
Head on over to the Works tab above to find more duets, such as the elementary-level nursery rhyme “We Are the Dinosaurs,” to the intermediate individual Piano I and II parts to “Pop! Goes the Weasel.”
My favorite small accomplishment as of late is a duet of Minecraft‘s BGM (background music) “In the Evening on Grassland,” for four hands on one piano (here’s the cruddy, pedal-less MIDI-reproduced recording):