The Ballooneridoo is a multiple note didgeridoo which changes the internal diameter of the didgeridoo-pipe by use of a balloon as the didgeridoo membrane and a foot bellow which by annular suction alters the diameter of the didgeridoo.

I'm only aware of one other instrument, the french horn which changes note based on the the internal diameter of the instrument. A french horn a player will insert their hand into the horn to alter the diameter and air resistance of the horn. With the ballooneridoo the pipe diameter is modulated by the foot, or elbow by strap mounted bellow, allowing the hands to remain free, and didgeridoo multi-note basslines to be played, useful for one-person band applications.

With the balooneridoo you can put water inside the annulus for it to have a more incompressible "pipe", or just a bit of water to see the didgeridoo sound wave cause water to vibrate. You can make a fire-doo with it by adding a reubans tube shell around the balloon and running combustible gasses through the annulus.

Step 1: Get Materials for Balooneridoo

You Need for Balooneridoo

A clown balloon
A clear plastic tube pipe, ideally polycarbonate or acrylic for a suction shell.
Two plumbers testing caps which fit your plastic suction shell.
A semi-rigid hose which will connect to the suction bellows and insert into the side of the plastic shell.
Small pieces of pipe, or lamp pipe which will fit into modified plumber test-plugs to act as nipples for the clown balloon to attach too, and a piece of pipe to T off the suction shell which the semi-flexible hose will connect to.

Step 2: Get Materials for Suction Bellows

You Need for the suction bellows,

A truck or tractor inner tube,
Plywood,
Spring or Springs. ( You can use mattress springs if you don't have access to a spring store, or use hydrostatic water pressure in suck your balloon in to didgeridoo shape. )
Hinge
Hose clamps, ( or banding tool ideally if you have access to one).
Bulk head fitting, or uniseal, or epoxy to have pressure right pump inlet.

*note, inflatable mattress pumps are not air-tight and won't hold vacuum or pressure longer then 5 minutes. You need to use a seamless membrane, like on a basketball, or radially dissected inner tube.

Step 3: Make Balooneridoo Shell, Attach Nipple

Drill hole in side of clear plastic acrylic or poly carbonate "shell" pipe.
Insert a nipple, fitting, or some way to attach a hose to it.

You can use epoxy, solvent weld acrylic or polycarbonate, or even use a heat gun to fit in standard pvc T-fittings and bush down to a hose size.

Make sure its pressure tight.

Step 4: Modify Plumbers Test Caps

Take bolt out of plumbers test caps.
Cut ends off.
(You might not have this brand of test cap. If you have a bolt going through the rubber, then its advisable to switch the bolt for lamp-pipe and washers, available at home depot, or some hollow non-flared pipe nipple which can tighten and expand the test-cap-rubber to create an annular plug. )

Glue, cement, solvent weld of compress a nipple sticking though the inside end of the test cap which is bigger diameter then the clown balloon, and long enough to attach an end of the clown balloon.

Step 5: Attach Balloon and Tighten Plugs, Attach Hose

Inflate balloon through the clear-shell. If the balloon is larger diameter then the shell and it gets caught, you can put a magnet inside of the balloon and guide and strech it using a secondary magnet in your hand through the shell.

Once through the shell, tie it, or tape it to the outside.

Cut the ends off both sides. Attach each end to the nipple on the test-cap-annular plugs.

Then Attach the test plugs to the clear shell and tighten.

Step 6: Make Bellows

Cut radial segment of a tractor inner tube.

Trace its shape onto 3/4 inch, or 1/2 inch plywood and use a band jaw or a job saw to cut a pump-shell. CNC if possible. There can't be any sharp curves in the shells if it will hold vacuum.

Trace your spring onto the plywood and route a groove for the spring to be placed in.
* make sure it is far enough away from the fold of the inner tube, or else it will bite a hole in the inner tube.

Use hole saw to cut a port into the shell, if you have a bulk-head fitting use that, if not you can use ABS threaded fittings to compress into the wood. You can hole saw cut a circular lip to the plywood for ABS fittings to bite harder and create a seal.

Attach the hinge. You can put a block to onto the plywood to raise the hinge for pivot motion, but I choose to position one pump-plate ahead of the other so one plate will rotate over the other.

Put the spring in and use hose clamps to tighten up the seal between the tractor inner tube and the plywood.

You can soap and water test the seal, and use silicon if necessary to get a pressure seal.

Step 7: Attach Hose and PLAY With Your New B.Doo

*Note if the spring isn't strong enough to suck the balloon diameter, fill the pump and annulus with water, the hydrostatic will suck the balloon into shape, and you can then use pressure for variable diameter, multi note experience while B. dooing.

Step 8: Water Dooing

You can poor water into the annulus if you want a more "incompressible didgeridoo-wall", this will help create a more solid didgeridoo sound, but bear in mind the the hydrostatic pressure will adjust the amount of spring force you need to suck the balloon into shape. The hydrostatic pressure might make it pressure based.

Or you can pour a little water and observe the sound wave visualization travel into water.

Step 9: Fire Dooing

To Make a fire doo, you need stronger parts, which are heat resistance.

Use a bicycle inner tube as the "balloon".

Drill out a reubans tube shell by buying a copper 2inch pipe.

use unions with reducers facing inwards and attach inner tube to nipples.

Solder parts together.

You can use propane with a regulator, and plum in to copper fittings, with a quick shut off valve, or use methane from your backyard anaerobic digester if you wish to opt for carbon neutral fire-dooing, however the bellows will have to be modified to have a check-valve 1 way gas discharge system.

You ca use a spark-gap lighter to ignite the flames as they come out, or a silicon nitride glow plug and electrical switch.

Enjoy the didgeridoo sound wave fire visualization. Always practice with a fire extinguisher, and test inner tube.

watch the fire.doo performance share here.

https://youtu.be/NaL0hHKZV64?list=PLgBDzmxLRxu5Ei_J1jls-8tY21Q0Xe5cX