Noctave
Born in Vienna, Czerny spent his whole life there. As a child he studied the piano with Beethoven; as an adult he gave up performing to teach, and his pupils included the young Franz Liszt. He published a very large body of work, including books of studies still in use today, such as Op. 299 and Op. 740. The Eight-Measure Exercises, Op. 821, gather a hundred and sixty very short pieces, each built around a single difficulty.
Each exercise in the catalogue lasts about twenty seconds, which suits Noctave's loop: you can repeat it without stopping until it becomes even. Start with No. 3, in C major, where the right hand keeps a moderate pace. No. 1 pushes that pace to six notes per second. No. 11, in B-flat major, is the most demanding of the three: octaves and repeated notes in the right hand, to be played from a supple wrist rather than the fingers alone.