Improvisation was a central practice to musicians for centuries within the Classical idiom. Although in Classical concerts of our time, improvisation is rarely heard, in the jazz sphere, it is still a core practice. I believe the heart of improvisation lies in a thorough, embodied knowledge of stylistic sentences and trademarks, the syntax of a language, and the ability to free-associate in the genre, according to a small set of boundaries. How did classical performers slowly lose this skill and why did it disappear from concert platforms? Drawing inspiration from great improvisers of the twentieth century, here is Oscar Peterson demonstrating the pianistic styles of contemporary jazz pianists:
This act of learning to demonstrate and improvise in the style of other famous jazz pianists created a vocabulary through which Peterson could learn to imitate and eventually speak in his own style. In other words, we can get closer to the practice of improvisation by first duplicating the styles of other Classical composers.
In parallel to Oscar Peterson's demonstration, Muzio Clementi published a print-version along very similar lines to the preceding "Piano Lesson". In exactly the same manner, he demonstrates a copious, first-hand, fluent knowledge of the styles of famous contemporary composers in the late eighteenth century. Separated by centuries and in a different idiom, the core practice of learning to improvise was the same. Here is a link to his Musical Characteristics, or a Collection of Preludes and Cadences, Op. 19: Click here.
Here is a clip of the cadenza that I wrote to Clementi's Sonata in B-flat major, Op. 24 No. 2, after studying his preludes and cadenzas in this volume.
“No one disputes the need for embellishments…Without them the best melody is empty and ineffective, the clearest content clouded.”
– C.P.E. Bach