In the penultimate measure of the first movement Clementi’s Sonatina No. 36, there is a short cascade of notes: This sonatina is often used as a teaching piece, because it’s a great introduction for the early intermediate pianist to the techniques required in more complicated piano pieces. This little cascade is a good example of why. It’s short, only eight notes long. In the numbering system every beginner learns, your thumbs are ones; your pinkies, fives. The G and A keys are right next to each other on the keyboard, and one might expect that the prescribed fingering of two adjacent notes would require two adjacent fingers. Perhaps, because the sequence continues down the keys, the four and five fingers, so that other fingers are properly positioned to reach the next notes.