Most instruments, with maybe the exception of pianos, have consumable parts. Guitars need string changes, bows need rosin, saxophones need reeds. [Co:Creation Lab]’s balloon banjo requires both fishing line and a party balloon, lest it be semi-silent.
If you want to change the resonance, just increase or decrease the amount of air inside the balloon. Neither the balloon nor the strings need tools to adjust, but we might argue that tuning pegs are tools.
The balloon banjo was the result of a design constraint: a parent should be able to build it with their child. To that end, there are no metal screws, no recurring snap-fits in the assembly, and a single, internal, one-time-use snap fit for the adult’s tactile satisfaction. Instead, the balloon banjo uses 3D-printed screws. A six-year-old can turn them with their fingers, and it’s difficult to over-tighten them and strip the plastic threads.
Be sure to check it out in action after the break. If you would rather use extant plastic to make music, the Bottlephone 2.0 is calling.