As a musical instrument, the jug provides a rhythmic bass accompaniment. Jugs produce sound when air is blown over the top opening. Larger jugs produce a deep musical tone and smaller jugs produce higher pitches. Most players use only one jug at a time, thus, play only one note. The pitch and volume are functions of the size and shape of the opening, the speed of the air blown across the top and, most importantly, the volume of air in the jug. That means that the pitch of a jug may be adjusted by adding water in the jug and that even a large jug may produce a higher note if it is mostly full of water.
The jug band was at the height of popularity in the 1920s, when such bands as Cannon's Jug Stompers were popular. Typically jug bands play folk music, either hillbilly or blues, but the 13th Floor Elevators, a psychedelic band from Texas, featured an "electric jug" in the 1960s.
Resonance section needed here. Any volunteer scientists?.
Rock climbers use the term jug to describe very large and deep hand holds.