The 17th century organ composers of Germany can be divided into two primary schools: the north German school and the south German school (sometimes a third school, central German, is added). The stylistic differences were dictated not only by teacher-pupil traditions and international influences, but also by separate organ building traditions: northern organs tend to have a tower layout with emphasis on the pedal division, while southern and Austrian instruments are typically divided around a window and emphasize manual divisions.
The composer who is now considered the founder of this school is Jan Pieterszoon Sweelinck, a Dutch composer (a student of his father Pieter Swybbertszoon and of Gioseffo Zarlino in Venice). Sweelinck's fame as a teacher was very widespread (in Germany he was known as the "maker of organists"), as was his influence. However, the English keyboard school withered during the first half of the 17th century, and the Dutch composers after Sweelinck were either not on his level (Anthoni van Noordt) or left too few compositions to make any significant mark on the history of European music (Pieter Cornet). Sweelinck's influence therefore was primarily important in Germany, Heinrich Scheidemann and Gottfried Scheidt being the first major composers to study under him.
Later northerners like Franz Tunder, Georg Böhm and Johann Adam Reincken all cultivated a harmonically and rhythmically complex improvisatory style rooted in the chorale improvisation tradition. Forms such as the organ prelude (a multi-sectional composition with numerous flourishes and embellishments such as scale runs, arpeggios and complex counterpoint) and the chorale fantasia (a musical setting of a whole verse of the chorale text, resulting in a multi-sectional composition with contrasting sections for different lines) were developed almost exclusively by north German composers. Dieterich Buxtehude's work represents the pinnacle of this tradition; the praeludia form the core of his work. Nikolaus Bruhns was the most important of Buxtehude's pupils, but he died early and only a few works by him survive.
The quality of north German organs improved vastly during the 17th and early 18th century. The instruments would typically have two or more manuals, a pedalboard and a wide range of stops; this contributed to the style cultivated across the region as the majority of large-scale works require considerable pedal skills and benefit from larger, more versatile organs.
The tradition of the south was shaped by composers who travelled to Italy or studied under Italian masters. The first important southerner was Johann Jakob Froberger, who visited Italy and France and cultivated Italian idioms in his toccatas (influenced by Girolamo Frescobaldi and Giovanni de Macque) and the French lutenists' style brisé in his harpsichord suites – he was also the first to establish the standard model for the suite, which was later used by both south and north German composers. Froberger's influence was felt all over Europe and extended far into the future: Albrechtsberger, Beethoven's teacher, knew and respected Froberger's work, and a copy of a part of one of his composition exists in the hand of Mozart.
Froberger did not have any significant pupils, but the other important southerner, Johann Kaspar Kerll, did achieve fame as a teacher and influenced numerous composers. Kerll initially studied under Giovanni Valentini, an Italian composer who worked in Vienna; he then travelled to Italy and visited many more regions of Europe. Kerll's influence was perhaps short-lived compared to Froberger's (the most important fact here being Händel's frequent borrowing from Kerll's work), but he was a model (perhaps even taught) for the Nuremberg-born Johann Pachelbel, whose work is the highest point of the south German tradition.
Typical south German organs differed from their northern counterparts and could have only a dozen or two stops, sometimes a single manual and, occasionally, no pedal; much like many Italian instruments. The music of south German composers on the whole concentrates more on melody, harmonic clarity and sound; genre-wise, Italian models were adopted and resulted in German versions of the toccata, a special brand of improvisatory preludes, and ostinatovariation forms: chaconnes and passacaglias. Perhaps the last significant southerner was Johann Heinrich Buttstett, Pachelbel's pupil, who continued the trends set by his teacher but did not achieve any considerable fame; it appears that numerous works by him are now lost.