Who: Dispatch

Members: Vocalists and multi-instrumentalists Brad Corrigan, Pete Francis Heimbold and Chad Urmston. And when we mean multi-instrumentalists, we mean they all play numerous music makers—and even swap them amongst themselves during live shows.

Their sound: In the tradition of the post-Grateful Dead jam scene, the New England trio is firmly ensconced in roots-rock, though it colors its crunchy, bluesy Americana with flourishes of folk, bluegrass, funk, reggae, ska, world music and even hip-hop. It’s essentially the one-band distillation of the modern improv rock scene, sans the livetronica sect, as Dispatch favors harmonicas and banjos over synthesizers—and, by extension, the acoustic, harmonic sound largely birthed on the East Coast college scene in the 1990s.

Stream now: “The General,” “Elias,” “Bang Bang,” “Josaphine.”

A truly DIY ascent: You likely haven’t heard of them, but Dispatch is one of the most successful independent rock bands of the past 20 years. It has become a textbook example of a band that gained a modest but loyal audience through grassroots promotion and word of mouth—sans a major record label or commercial radio airplay—then quietly exploded in popularity during the advent of Napster and digital file-sharing.

How to say goodbye—and hello: Dispatch announced a hiatus in 2002, then a final concert in Boston in 2004, which resulted in one of the great pilgrimages in rock history: an estimated 166,000 people, many of them crossing oceans and continents to make the trek. When it announced a one-off charity show three years later, Dispatch ended up quickly selling out three nights at Madison Square Garden, solidifying its status as one of rock’s biggest cult bands. In 2011, it officially reunited with a major American tour and its first new music in years. For its most recent material, check out the 2017 full-length America, Location 12.

Dispatch with Nahko and Medicine for the People. August 17, 6 p.m., $40-$55. Brooklyn Bowl, 702-862-2695.