Haydn’s keyboard concerto in G major, Hob. XVIII:4, was written during Haydn’s employment at the Esterházy court (1761-1790), probably around 1770. It was first published in 1784 by the Parisian editor Boyer, and performed on 28th April of the same year at the Concert Spirituel in Paris by the blind pianist Maria Theresia von Paradis. In September 1784 Mozart wrote his keyboard concerto no. 18 (K. 456) in B flat major for the same pianist.
Not taking into consideration the concerto for harpsichord and violin or the small-scale concertini and divertimenti, we know of only three authentic concerti by Haydn intended to be performed on the harpsichord or fortepiano (thus not on the organ). These are the concerti in F major (Hob. XVIII:3, ca. 1765), in G major (Hob. XVIII:4, ca. 1770) and the famous concerto in D major (Hob. XVIII:11, before 1784).
Unlike Mozart (who wrote 27 keyboard concerti), therefore, it would perhaps be difficult to argue that Haydn made a major contribution to (the development of) this genre. He probably made more impact with his piano trios, piano sonatas, string quartets and symphonies. In fact, most music lovers know only of his D major concerto.
One possible explanation for Haydn’s relative lack of devotion to this popular genre might, of course, be his own fairly moderate, even if competent, keyboard skills. Mozart was much more of a keyboard virtuoso, frequently and spectacularly perfoming his own works in public.
The beautifully-written concerto nr. 4 in G major is a very interesting and pianistically appealing work.
The ritornello form of the dramatic opening Allegro of Hob. XVIII:4 and its traditional keyboard style remind us of the Baroque concerto. The virtuosity, the expressive chromatic harmony and the modulatory passages, however, reveal more progressive development.
The Adagio (in C major), with muted strings, is surprisingly simple, but at the same time expressive and sombre. The 3rd and final movement is a witty and resourceful rondo in 2/4 time. In this movement Haydn wrote out the cadenza himself.