Jamgrass

Jamgrass is a form of progressive bluegrass built around extended improvisation, in which string bands stretch songs into long, exploratory jams in the manner of rock jam bands. Banjo, mandolin, fiddle, guitar, dobro and upright bass remain the core instruments, but the repertoire opens to rock, folk, jazz and psychedelic material, and sets favour open-ended soloing over tight traditional arrangements. Emerging from the American festival circuit in the 1990s, it treats the concert rather than the studio album as its centre, with live recordings, sit-ins and multi-night runs defining its culture.