Sonatas K. 1 - K. 30

Among Scarlatti's keyboard sonatas, K. 1 to 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 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 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 a short imitation between both hands; in many cases, the imitative figure appears to have little direct relation 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 expressions of humility or formality.

K. 30 in G minor, FUGA, Moderato

The only four-voice fugue within the Essercizi, known as the 'Cat Fugue'. Sutcliffe (2003) is critical of the interpretation that K. 30 is an expression of respect for older counterpoint, pointing out that 'contrapuntal smoothness' is avoided. Overall, the piece features sections where the subject and countersubject form chordal progressions, and a relatively high proportion of sequences. Furthermore, dissonant sonorities, including the augmented second and diminished fourth progressions in the subject, also characterize the work.