of twelve years old play the most difficult sonatas on the harpsichord, while her brother accompanied her impromptu on another harpsichord." Wolfgang performed on a harpsichord with two manuals and a pedal which the musical instrument maker Tschudi had constructed for the King of Prussia;[20036] Tschudi "rejoiced that his extraordinary harpsichord should be played for the first time by the most extraordinary performer in the world." After this, L. Mozart repeatedly invited the public to hear and test the young wonder in private daily from twelve to two o'clock; at first these performances took place in their own lodging, afterwards in a tavern, not of the first rank. It was promised as something extraordinary that the two children should play a duet on the same clavier with the keyboard covered. It was for these occasions that Wolfgang composed his first duet, according to L. Mozart, the first sonata for four hands ever written. The Hon. Daines Barrington, a man highly esteemed as a lawyer and a philosopher, undertook a repeated and searching trial of the boy's skill, and has left a circumstantial report of the result.[20037] He obtained a copy of Wolfgang's registry of baptism, in order to be sure of his age, and made other minute inquiries concerning him. Besides the usual tests of playing difficult pieces at sight, and of singing and accompanying with proper expression a score hitherto unknown to him, he demanded an improvisation. He told Mozart to improvise a love-song such as Manzuoli might sing in some opera. The boy at once pronounced some words to serve as a recitative, then followed an air on the word _affetto_ (love) of about the length of an ordinary love-song in the regulation two parts. In the same way he composed a song expressive of anger on the word _perfido_ which excited him so much, that he struck the clavier like one possessed, and several times sprang up from his seat. Barrington remarks that these improvised compositions, if not very astonishing, are {HOLLAND, 1765.} (43) yet far above the ordinary run, and give proofs of decided inventive power. Not only has Mozart's technical education so far advanced, that he handles freely the forms and rules of composition; he begins now to display the inspired imagination of an artistic genius. It is interesting to note the first stirrings of the dramatic element in Mozart, and how he was able already to give articulate expression to various passions as they were suggested to him. An instance of this is a tenor song, "Va dal furor portata" (21 K.), composed in London, 1765, in which the Da capo form is rigorously adhered to, and which, though wanting in originality displays much sense of characteristic expression.