The German musician, astronomer and chronologer, Sethus Calvisius (originally: Seth Kalwitz or Kallwitz), was born of a peasant family at Gorschleben in Thuringia. His poverty interfered greatly with his education, but he contrived to attend the Magdeburg Gymnasium in 1572, and the Universities of Helmstedt (1589) and Leipzig (1580) and to avail himself of every opportunity of musical instruction.
By the exercise of his musical talents Sethus Calvisius earned money enough for the start, at Helmstedt, of a university career. The aid of a wealthy patron enabled him to continue at Leipzig, where he was made 'repetent' at the Pauliner Church in 1581. He became director of the music-school at Pforten in 1582, and served in this post for 12 years. In 1594 he was transferred to Leipzig, where he became Kantor and Schulcollege at the Thomasschule, and music director at the Thomaskirche of Leipzig. He retained this post until his death on the November 24, 1615, despite the offers successively made to him of mathematical professorships at Frankfurt and Wittenberg (1611). So much the music was important to him.
In his Opus Chronologicum (Leipzig, 1605, 7th ed. 1685) Sethus Calvisius expounded a system based on the records of nearly 300 eclipses. An ingenious, though ineffective, proposal for the reform of the calendar was put forward in his Elenchus Calendarii Gregoriani (Frankfurt, 1612). He is best known for a book on music Melopoeia sive melodiae condendae ratio, quam vulgo musicam poeticam vocant (Erfurt, 1592; Magdeburg, 1630), based on Zarlino's Le istitutioni harmoniche and including a chapter on poetic and musical figures and their relationship. He discusses modes and the history of music theory in Exercitationes musicae duae (tertiae) (Leipzig, 1600 and 1611). He also wrote purely didactic musical treatises. His other treatises are: Compendium musicae practicae… (Leipzig, 1594; 2nd ed. 1602), Musicae artis praecepta… (Leipzig, 1612; 3rd ed. of the Compendium).
Sethus Calvisius' music, original and edited, comprises: 'Hymni sacri et germancini', 1594, 'Harmonia cantionum, a M. Luthero… compositarum' (Leipzig, 1597), pedagogical works as 'Bicinia 70', 1599, 'Bicinorum libri duo…' (Do. 1590 and 1612), and 'Tricinia…', (Do. 1603). He also composed 4-part settings of the Psalms and of sacred hymns and songs in Latin and German, such as 'Der 150 Psalm für 12 Stimmen…' (Do. 1615); 'Schwanengesang' for 8 voices, 1616, 'Der Psalter Davids…' (Do. 1617), and a few motets. Many motets and hymns are in manuscript in the library of the Thomasschule, and his pretty 'Joseph, lieber Joseph mein' is in Vol. III of Arion. A full catalogue of manuscripts and editions id in Eitner's Quellen-Lexikon.