Best understood as a single concept split into two actual ensembles--Amon Duul I and Amon Duul II--with a shared origin and vision, Amon Duul is arguably the quintessential example of the style of music known as Krautrock. Born out of Germany's hippie art scene of the late 1960s, the Amon Duul name had divided into two separate entities by 1969, with the original band choosing a more free-form, improvisational approach to music making, while its sequel (and often contemporary) chose a more rigorous, technically adept progressive sound. Both acts went through various line-up changes over the subsequent decades, continuing to perform into the new millennium and benefiting greatly from the resurgent interest in German avant-garde music that took place in the late 1990s.