Loys "Louis" Bourgeois (; c. 1510 – 1559) was a French composer and music theorist of the Renaissance. He is most famous as one of the main compilers of Calvinist hymn tunes in the middle of the 16th century. One of the most famous melodies in all of Christendom, the tune known as the Old 100th, to which the Protestant doxology is often sung, is commonly attributed to him. Life Knowledge of his early life is sparse. His first publication, some secular chansons, dates from 1539 in Lyon. By 1545 he had gone to Geneva (according to civic records) and become a music teacher there. In 1547 he was granted citizenship in Geneva, and in that same year he also published his first four-voice psalms. In 1549 and 1550 he worked on a collections of psalm-tunes, most of which were translated by Clément Marot and Théodore de Bèze. The extent to which he was composer, arranger or compiler was not certain, until a long-lost copy of the Genevan Psalter of 1551 came to the library of the Rutgers University. In an Avertissement (note) to the reader Bourgeois specifies exactly what his predecessors had done, what he had changed and which were his own contributions. He is one of the three main composers of the hymn tunes to the Genevan Psalter. Unfortunately, he fell foul of local musical authorities and was sent to prison on 3 December 1551 for changing the tunes for some well-known psalms "without a license." He was released on the personal intervention of John Calvin, but the controversy continued: those who had already learned the tunes had no desire to learn new versions, and the town council ordered the burning of Bourgeois's instructions to the singers, claiming they were confusing. Shortly after this incident, Bourgeois left Geneva never to return: he settled in Lyon, his Geneva employment was terminated, and his wife tardily followed him to Lyon. While in Lyon, Bourgeois wrote a fierce piece of invective against the publishers of Geneva. His daughter was baptized in Paris in May 1560 (as a Catholic), and also in 1560 a Parisian publisher posthumously printed a volume of his secular chansons – a form he had condemned as "dissolute" during his Geneva years. Music and influence Louis Bourgeois is the one most responsible for the tunes in the Genevan Psalter, the source for the hymns of both the Reformed