During the first decades of its existence, jazz was uniquely American. From London, where Louis Armstrong performed before King George V, to Bangkok, where King Bhumibol Adulyadej became an accomplished improviser, American jazz was admired and imitated, but only a few musicians were able to make original contributions to the art. Like so much else, this all changed in the 1960s, when players in England, France, Germany, and the Netherlands, inspired by the free jazz movement across the Atlantic, took radical steps towards musical independence, searching for means of expression that would reflect their own cultural experiences. While enamored of jazz history, they often broke with historical and generic constraints, seeking inspiration in older jazz forms, in contemporary pop and classical music, and in folk traditions from many places. As their art matured, the European improvisers began to influence new generations in their own countries and in the United States as well.

This feedback and the internationalization of improvised music are well represented in the quartet led by saxophonist/clarinetist/flutist Gebhard Ullmann and trombonist Steve Swell. Both were born in the late fifties, at the cusp of the jazz revolutions, the former in Germany, the latter in New Jersey. Their backgrounds were quite different, but they eventually ended up playing in similar contexts. Swell took the traditional American route: he learned his instrument at school, moved to New York, and ended up as a professional, playing in Broadway pits and traveling big bands, making a good living. Around 1985 he abandoned this lucrative but sterile work and dedicated himself to more creative endeavors. He began to play with like-minded musicians in New York’s “downtown scene,” centered on the Knitting Factory, and eventually began to lead his own groups, honing his compositional as well as his instrumental techniques.

Ullmann’s German career followed a parallel path. After traditional and jazz studies in Hamburg, he moved to Berlin in 1983, just about the same time that Swell came to New York. A well-trained multi-instrumentalist and already an accomplished composer, he fell immediately into the heterogeneous musical environment of Germany’s cultural capitol. His early recordings reflect the multiple streams of tradition characteristic of Berlin’s musical world, using instruments such as the accordion and referencing a broad range of sources, from older jazz forms to European avant-garde traditions to Kurt Weill. He plays many instruments, but now focuses on tenor saxophone, bass clarinet, and the bass flute. Like Swell, he leads a number of groups–from duets and trios to larger ensembles–and has recently been performing solo.

Swell and Ullmann come from different backgrounds and play different instruments, but they have many things in common, including a love of composition as well as improvisation and a highly physical approach to playing. This is hardly tame music: framed by the leaders’ compositions, the improvisations are often extremely dynamic, and the main focus is on musical interaction. In tandem with bassist Hill Greene and the pioneering drummer Barry Altschul, they will roar at the Kerrytown Concert House on April 10.