The term "jam band" is used to categorize a type of music that favors improvisation and musicianship over concise riffs, hooks, and traditional songwriting structure. The term also helps define the fiercely dedicated fans of the music as accurately as it does the bands. Much as with the Grateful Dead -- the progenitors of the jam band scene -- the survival of the scene depends upon a symbiotic relationship with fans. Jam bands nurture a close relationship with their fans, fostered through constant touring and the mutual belief that each performance is a unique, shared event.

JAMerica tells the story of the roots, evolution, values, and passion of the jam band scene in the words of those who know it best. Modeling itself on such books as Edie: American Girl by George Plimpton and Jean Stein (an oral history of the life of Edie Sedgewick ) and Please Kill Me: The Uncensored Oral History of Punk by Legs McNeil and Gillian McCain, the book is an oral history of the jam band scene, integrating stories from such bands as the Grateful Dead, Phish, Widespread Panic, Dave Matthews Band, moe., Leftover Salmon, String Cheese Incident, Umphrey's McGee, and dozens more. Interviews focus on the history of individual bands and how they communally shaped the larger jam band community, along with songwriting, relationships with fans, business models, and the importance (including the joys and war stories) of touring, including early gigs and venues (e.g. the Wetlands in New York City and the landmark H.O.R.D.E. Festival) that supported the emergence of the jam band scene.