Waldkirch, most famous for its barrel organs, hosts an organ festival every 3 years with participants form all over the world. Regularly, more than 100 exhibitors participate in an event that lasts for 3 days. The 8th Festival took place between 17th to 19th June 2005, the 9th in June 2008.
A barrel organ is a musical instrument made of pipes, and bellows, like any other traditional organ, and of a cylinder studded with staples or bridges or pins corresponding in their placement to a particular tune. While the cylinders are called barrels, they are usually much smaller than the barrels used as storage containers for several centuries. Usually made of finely crafted metal, the organ barrels has to be extremely sturdy in order to keep their precise alignement over the years. The continuous rotation of the barrel causes the staples to come into contact with levers and rods which open valves to let air from the bellows into the organ pipes. The bellows are actuated by the same power source which, through reduction gearing or worm gearing, causes the drum to slowly turn around.
There are many large organs located in churches throughout Elztal. The large barrel organs were often powered by very heavy counterweights and springs, like a more powerful version of a grandfather clock. They could also be hydraulically powered, with a wheel arrangement giving the mechanical force while columns of water forced greater pressure in the columns of air which sounded the pipes.
The sound differs in several respects from other keyboard instruments. In particular: the sound output is continuous, i.e. the sound of the organ usually continues for as long as a key is held down. In contrast to a piano, the organ is weaker in sense of rhythm and tempi but has a better sense of pitch. The sustained notes are easier to sing along with an organ than with an instrument that decays without sustain. The change to the sound depends on how far down a key is pressed, rather than how hard the key is struck as with a piano.
The original organs produced in Waldkirch were pipe organs and can be divided into two categories: Firstly, the church organ developed originally for singing, and still found in many Elztal churches mostly accompanied by a choir. Often just called a pipe organ, it may be called a church organ or classical organ. The line between a church and a concert organ is hard to draw. Instruments of any size may include some stops designed for independent performance of this music rather than for accompaniment.
Secondly, the theatre organ was designed to replace orchestras or instrumental ensembles that accompanied silent movies with a single performer. The concert organ or symphonic organ flourished during the beginning of the twentieth century developed primarily to perform repertoire originally written for the church organ.