Used for rhythmic accompaniment, the jug as a musical instrument reached its height of popularity in the 1920s, when jug bands were popular.

The jug is usually made of glass or stoneware and played with the mouth. With an embouchure like that used for a brass instrument, the musician holds the mouth of the jug about an inch from the mouth and emits a blast of sound, made by a "buzzing" of the lips, directly into it. The jug does not touch the musician's mouth, but serves as a resonating chamber to amplify and enrich the sound made by the musician's lips. Changes in pitch are controlled by loosening or tightening the lips, and an accomplished jug player might have a 2 octave range. Some players augment this sound with vocalisations, didgeridoo style, and even circular breathing.

In performance, the jug sound is enhanced if the player stands with his back to a wall, which will reflect the sound toward the audience.

As a bass instrument, the jug is part of the band's rhythm section, but jug solos are common. Most jug bands use a single jug player, but there are recordings of period bands that used jug sections of two or more players.