This piece of music by John Christopher Smith [1712-1795] was published in 1755. It is from Harpsichord Sonata in A major that has 3 movements: Allegro, Larghetto and Vivace.
Smith was the secretary of George Frideric Handel [1685-1759] in the last part of Handel's life. Before that his father John Christopher Schmidt [1683-1763] had had the same role for many years until a quarrel with Handel ended the collaboration.
William Cox [1748-1828] who in 1760 became stepson to Smith Jr. wrote in 1799 in 'Anecdotes of George Frederick Handel and John Christopher Smith' the following about how the German Schmidt family ended up in England:
"John Christopher Smith was born in 1712. His father John Christopher Schmidt (Schmidt was the German name corresponding with the English appelation Smith), of Anspach in Franconia, after receiving a good education in the university of Halle, married a lady with a portion of seven thousand crowns, and settled in his native city. He carried on a considerable branch of traffic in the woollen trade, in which he might have acquired a large fortune, had he not been seduced by his passion for music; when Handel arrived at Anspach in 1716, he renewed an acquaintance which had commenced at Halle, and soon became so captivated with that great master's powers, that he left his wife and children in Germany, and accompanied Handel to England, where he regulated the expences of his public performance, and filled the office of treasurer with great exactness and fidelity. On the fourth year of his residence in England, he sent for his wife and family, which consisted of a son and two daughters."
Pictures of settings concerning the sound of the music in the video: