It became an open exchange and performance place for young experimental artists, poets and musicians in the Frankfurt area with the Just Music ensemble as a main creative pool.
American clarinetist Tony Scott played there with Just Music and also in the following years Harth and Just Music kept open to perform with many others as the German musicians trumpetist and composer Michael Sell (with the Free Jazz Group Wiesbaden), saxophonist Peter Brötzmann and tuba and bassplayer Peter Kowald, Czech flutist Jiri Stivin, members of the AACM, Polish violinist Zbigniew Seifert, American saxophonist Anthony Braxton a.o.
In 1971 Harth and Van den Plas started to focus on duo works and in 1972 with guests as Peter Kowald and drummer Paul Lovens a.o.
Their music was mostly experimental, making classification all but impossible and contained an extreme variety of timbres and dynamics at the basis of a spontaneous expression.
Since the mid-1960s Alfred Harth was open to all creative horizons influenced by the Stuttgarter Schule around Max Bense, zen and the fluxus events in nearby Wiesbaden.