early baroque organ music in germany was highly contrapuntal. sacred organ music was based on chorales: composers such as samuel scheidt and heinrich scheidemann wrote chorale preludes, chorale fantasias, and chorale motets. towards the end of the baroque era, the chorale prelude and the partita became mixed, forming the chorale partita. this genre was developed by georg böhm, johann pachelbel, and dieterich buxtehude. the primary type of free-form piece in this period was the praeludium, as exemplified in the works of matthias weckmann, nicolaus bruhns, böhm, and buxtehude. the organ music of johann sebastian bach fused characteristics of every national tradition and historical style in his large-scale preludes and fugues and chorale-based works. towards the end of the baroque era, george frideric handel composed the first organ concertos.