[3] After starting his musical education in Velvary, Koželuch moved to Prague where he studied with his cousin and František Xaver Dušek, the latter teaching him in the keyboard and composition.

Pianist Kemp English observes that in Vienna Koželuch "found himself in the right place at the right time", and was able to advance his career there with carefully cultivated connections.

[3][1] By 1790, a time at which Mozart and Joseph Haydn were at the height of their careers, Koželuch's reputation was such as to move Ernst Ludwig Gerber to say the following of his status within Europe: "Leopold Kozeluch is without question with young and old the generally most loved among our living composers, and this with justification".

[6] Koželuch's esteem in royal circles grew again in 1791, when he composed a well-received cantata commissioned for the coronation of Emperor Leopold II in Prague.

[2] Koželuch joined a masonic lodge in 1791, marking another coincidence between his career and Mozart's and serving to advance himself further within Viennese society.

[4] Koželuch's compositional output declined after the turn of the century as he focused on his court duties, teaching, and the lucrative work of arranging Scottish, Irish and Welsh folk songs for the publisher George Thomson.

Christopher Hogwood argues that Koželuch's keyboard sonatas, especially those which open in minor keys, "substantially anticipated ... the tragic-pathetic manner" of Beethoven and Schubert, and that in them he "created the internationally praised cantabile idiom".

The musicologist Richard Wigmore argues that they "conspicuously lack the melodic abundance, rich woodwind colouring and operatic-style dialogues of Mozart's great Viennese concertos", but nonetheless "beguile with their limpid grace, their sparkling keyboard writing (often in just two parts), and their sense of proportion.

[10] Musicologist Roger Hickman refers to this period of chamber music output as representing a more "daring character" on the part of the composer, and argues that these works "must have been noted by the young Schubert".

[6] Koželuch probably composed most of his symphonies during his first decade in Vienna, a period in which his Viennese contemporaries, including Mozart, were focusing on other genres.

Badley argues that Koželuch's symphonies are influenced by those of his Prague teacher František Xaver Dušek in their orchestration and thematic organisation.