Leopold Mozart became a violinist at the court of the Prince-Archbishop of Salzburg and rose through the orchestra's ranks to become court composer (1757) and (1762) vice chapelmaster. His treatise setting forth his method of teaching, Versuch einer gründlichen Violinschule (A Treatise on the Fundamental Principles of Violin Playing), coincidentally published in 1756, the year of Wolfgang's birth, was long a standard text and was widely reprinted and translated. Among his musical compositions are concerti for various instruments, symphonies, and other pieces.

In 1763 he began the first of many triumphant and highly publicized exhibitions of his two talented children (the other five of his seven children did not survive infancy): Maria Anna (Nannerl; 1751–1829), an accomplished clavierist, and the precocious genius Wolfgang Amadeus, who, at age six, performed his own and others' works on several instruments, improvised, and played at sight difficult, unfamiliar compositions. Although often criticized for exploiting his son and commercializing his talents, Leopold Mozart sincerely felt it was his God-given obligation to develop such abilities and to exhibit them to the world. Some of the extensive correspondence of father and son is contained in The Letters of Mozart and His Family (1963), by E. Anderson.

Leopold Mozart's obsessional relationship to his son has been the subject of much speculation. His troubled relationship with his own birth family; the traceable (and scarcely benign) imprint of his obsession on Wolfgang's personality, career choices, and music; and the peculiar arrangement by which he undertook to raise his daughter's son (also named Leopold), as if to compensate for his own son's “betrayal,” combine to make this a particularly dark subject. Certainly, in Leopold's final decade he did much to undermine the enormous support and benefit that flowed to him as a result of his dedication to Wolfgang's early training.