The piece
The third piece in the Album for the Young is, in German, a Trällerliedchen: a little song to hum. The melody circles in quarter notes around C and G, over a left hand in eighths that brings back a G on every other note. In the central section the right hand takes over the accompaniment while keeping a sung line, and the left hand carries a melody in the bass. The opening then returns, slightly varied.
The left hand has to keep its eighths even, at about three notes per second, while lightening the G that keeps coming back: it's the moving note beneath that carries the harmony. Above it, the melody should stay supple and free of bumps. The middle section is the real work: there the right hand plays two voices at once, a line in quarter notes and eighths that keep returning to D or G, and the upper note has to stay in front. Practise very slowly at first, holding each quarter note while the other fingers play the eighths, then add the left hand.