The German composer and organist, Jacob [Jacobus, Jakob] Praetorius [often referred to by his German last name Schultz(e)], was born into a family of famous organists. His grandfather Jacob (? - 1586) and his father Hieronymus Praetorius (1560-1629), who was his first teacher, were both organists at the main church in Hamburg, the Jakobikirche. Jacob became a pupil of Jan Pieterszoon Sweelinck in Amsterdam (1601-1603). He seems to have been one of the great organist's first pupils, and Sweelinck even wrote a motet for his pupil's wedding in 1608. Succeeding Heinrich thor Molen, he became in 1603 organist of the church of Petrikirche (St. Peter) in Hamburg, a position he held until his death. He also undertook his father's duties at S. Gertrud after the death of the latter in 1629.
Jacob Praetorius enjoyed a great reputation as a teacher and organ player. In his Grundlage einer Ehrenpforte (Hamburg, 1740) Johann Mattheson wrote that Praetorius "had a particular, unusual but efficient finger technique. Schultz adopted Sweelinck's perfectly agreeable and respectable habits and behavior, he kept his body from making any superfluous movements, and while playing he gave the impression of not making any effort." Even during his lifetime Praetorius was already compared to his colleague Johann Heinrich Scheidemann, the other great Hamburg student of Sweelinck, and organist at the Katharinenkirche. Mattheson described Scheidemann as a rather nice and affable man, who "did not make too great a deal of himself. […] His playing was vigorous, awake and honest, he had fast and firm hands, and he was well trained in composition technique, but his music was destined only for the organ. His pieces were easy to play". On the other hand, Praetorius "was always regal and somewhat odd, he adapted the noble character of his teacher and showed extreme amiability in all his activities, as the Dutch always do. […] Schultz's pieces were more difficult to play and more elaborate, which put this composer above everyone else." In his chronicle of organists (1702-1718), Johann Kortkamp wrote of Praetorius that he was "esteemed by all people of high and low class. From his youth, he has acquired a special method in church music style, playing with majesty and devotion, and he was capable of animating people's hearts to listen to the sermon. Thanks to his great knowledge and with God's help he has taught many organists, who, at times were needed in Germany, and helped them with his recommendations. This amiable man should also be remembered for his sensual and artistic playing. Just like the priest with his parishioners, he was able to induce devotion with his organ playing. For example when he played a hymn like Erbarm Dich mein o Herre Gott, how well he played it with devotion; how well he was able to use the various stops for their specific qualities, so that not only his playing, but also the organ itself had to be admired." We also find Praetorius' qualities in his compositions: contrapuntal rigor is always combined with the pleasure of virtuoso playing. Among his students, Berendt Petri (born between 1594 and 1598 - ?) and Matthias Weckmann (1615/1616-1674) were the most renowned; the latter became organist at the Jacobikirche in Hamburg in 1655.
Three of Jacob Praetorius' motets were included in the first volume of his father's Opus musicum, and he was also one of the contributors to the Hamburger Melodeyen - Gesangbuch of 1604. Vocal works include approximately 30 motets and chorals, including nineteen in Melodeyen Gesangbuch (1604) and 10 in Neuer Himmlischer Lieder Sonderbahres Buch (1651). Instrumental works for organ include preludes, Magnificats, and chorals. His other works, as enumerated in Q.-L., are chiefly motets for weddings after the fashion of the time.