About Sonatas K. 1 - K. 30

Among Scarlatti's keyboard sonatas, K. 1 to 30, numbered according to the generally estimated composition dates by Kirkpatrick, were published as Essercizi per Gravicembalo and dedicated to King João V of Portugal in return for the bestowal of a knighthood. (This collection is generally translated as Exercises for Harpsichord, and while Scarlatti's works for keyboard instruments are primarily presumed to be for harpsichord, 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 himself.

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 dates, many researchers argue for an early composition period, 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 being arranged to become 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 the hands; in many cases, the imitative figure appears to have little apparent connection to the main material of the rest of the piece.

It should be noted that 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. 25 Allegro

As a practice in performance technique, the primary focus is likely on the left hand's movement crossing over the right hand. A central motif, alongside hand crossing, is a descending figure beginning with two 32nd notes. This appears repeatedly and is monotonously reiterated, but variations are introduced in places, such as its initial two-bar sequential unit later being shortened to one bar, or the bass line developing into chords in the latter half.