It's an interesting irony – Mozart composed his Symphony No. 33 (K. 319), with its vivacious opening and beginning-to-end loveliness, before a backdrop of impending financial disaster and professional dissatisfaction.
Mozart wrote the symphony in 1779, upon returning to his dissatisfying job in Salzburg after a frustrating stint in Paris. By November 1785, Mozart was desperate for cash and sent his publisher Franz Anton Hoffmeister a plea for help. "I turn to you in my distress," Mozart wrote, "and beg you to help me out with some money, which I need very badly at the moment." (The Letters of Mozart and His Family, trans. Emily Anderson).
The following August, Mozart wrote his friend Sebastian Winter, valet to the Prince von Fürstenberg, responding to an earlier letter in which Winter inquired on behalf of the prince about the possibility of purchasing some of Mozart's works. At the end of his letter to Winter, Mozart wrote the opening melodies of a number of his compositions up for sale, including his Symphony No. 33.
Mozart also took the chance to create other opportunities for himself with the prince. First, he offered the prince preferred access to his new compositions, writing Winter, "If His Highness should so desire, I shall send him in future all new works which I compose."
Then he offered the prince's orchestra exclusive performance rights to his new works. "Further," Mozart continued, "As His Highness possesses an orchestra, he might like to have works composed by me for performance solely at his court, a thing which in my opinion would be very gratifying."
Finally, he went for the gold, offering his services as a salaried composer to the prince. Mozart wrote Winter, "If His Highness would be so gracious as to order from me every year a certain number of symphonies, quartets, concertos for different instruments, or any other compositions which he fancies, and to promise me a fixed yearly salary, then His Highness would be served more quickly and more satisfactorily, and I, being sure of that commission, should work with greater peace of mind."
It was a bold series of moves, and the cash-strapped Mozart can't be blamed for making them. Mozart never became a court composer to the prince. But in the end, the prince did purchase several of the works Mozart offered him through Sebastian Winter, including his Symphony No. 33.