About Sonatas K. 1 - K. 30

Among Scarlatti's keyboard sonatas, K. 1 to K. 30, numbered according to their generally estimated composition dates (Kirkpatrick numbers), were published as Essercizi per Gravicembalo and dedicated to King João V of Portugal in return for the knighthood bestowed upon him. (This collection is generally translated as 'Exercises for Harpsichord,' and Scarlatti's works for keyboard instruments are primarily presumed to be for harpsichord; however, the current state of research does not definitively rule out other keyboard instruments.) This was the only collection published by the composer himself during his lifetime, and its preface holds value as an authentic documentary source by the composer.

The preface suggests that the collection aims at the cultivation of performance technique, leading to the inference that it was written for the practical purpose of daily practice for Maria Barbara, whom he served as a music teacher. Regarding the composition date, many researchers argue for an early composition date, viewing the Essercizi as revisions of sonatas written considerably earlier, but no definitive conclusion has yet been reached.

The arrangement of all 30 pieces allows for progressive learning, with later works generally becoming longer and more difficult. The form is fundamentally binary. Furthermore, it is typical of Scarlatti's sonatas for the opening of a piece to feature brief imitation between both hands; in many cases, the imitative figure appears to have little apparent connection to the main material of the rest of the piece.

The preface also contains remarks touching upon the overall musical content of the collection, but their interpretation has been repeatedly debated, partly due to the preface being a text prone to humility and conventional expressions.

K. 20 Presto

In contrast to works up to K. 19, the second half is short, approximately one-third the length of the first half, with most sections from the first half omitted. Similar to K. 11 and others, both hands concentrate on the high register, and the use of the low register is limited to cadences. The music undergoes fluid changes, such as sudden alternations between major and minor keys, and shifts from bright-sounding two-part parallel writing to a texture characteristic of the galant style, with a melody in the upper voice and accompaniment in the lower voice.