Johann Karl Rochus Ordoniz, also known as Karl von Ordonez (April 19, 1734–September 6? 1786) was one of a number of composers working in Vienna during the second half of the Eighteenth century. Ordonez was not a full-time professional musician. Most of his working life was spent in the employment of the Lower Austrian Regional Court and his musical activities were pursued in his spare time. Ordonez's choice of career was probably dictated by his social rank. As a member of the nobility, albeit of the lowest rank, he would have been aware that a professional musical career would not have befitted a man of his social standing.
Nothing has come to light concerning his general education. However, as a member of the lower classes of the nobility, he may have attended a Ritterakademie, a boarding school for the nobility, and considering his legal career, may have gone on to study law at the University of Vienna in preparation for entry to the civil service. Of his musical training we also known nothing although from his contemporary reputation as a violinist it can be inferred that he received lessons from an early age.
Ordonez's professional activities included membership of two prestigious performing bodies: the k.k. Hofund Kammermusik (where he was employed as a Kammermusikus) and the Tonkünstler-Societät in which he was active both as a violinist and as a composer. Ordonez was an early member of the Tonkuenstler-Societaet, an organization devoted to raising money through public concerts for the widows and orphans of musicians, and maintained a close association from 1771, the year of its foundation, until 1784. Ordonez also performed regularly in the houses of the nobility. Dr Charles Burney heard him play at a musical dinner party in 1772 held in the residence of the British Ambassador in Vienna, Lord Stormont:
Between the vocal parts of this delightful concert, we had some exquisite quartets, by Haydn, executed in the utmost perfection; the first violin by M. Startzler (J. Starzer), who played the Adagios with uncommon feeling and expression; the second violin by M. Ordonetz; Count Bruehl played the tenor, and M. Weigel (F.J. Weigl), an excellent performer on the violoncello, the base. All who had any share in this concert, finding the company attentive, and in a disposition to be pleased, were animated to that true pitch of enthusiasm, which, from the ardour of the fire within them, is communicated to others, and sets all around in a blaze; so that the contention between the performers and hearers, was only who should please, and who should applaud the most!