A musical group that uses jugs and washboards and kazoos and other improvised instruments WordNet 3.0 & Open English WordNet

A jug band is a band employing a jug player and a mix of conventional and homemade instruments. Wikipedia

Band employing a jug player Wikidata

Especially in the US, a group of rustic musicians, specializing in bluegrass or folk music, whose instruments include empty jugs, bottles, and similar containers of various sizes which produce musical sounds when the player blows across the openings at the tops of their necks. Wiktionary