We don't find tap dancers performing in their bare feet.
We don't find them wearing combat boots, either.
In ANY performing art, the proper footwear has everything to do with the execution of coordinated moves made by the legs and feet.
Organ playing is no different.
Playing the organ in street shoes is acceptable as long as they're of the right construct and made of the right materials [See blog, Balance in Organ Playing, Part I], but many teachers request that their students obtain special shoes for organ playing.
In areas of the world where special organ shoes may be difficult to obtain, other types of shoes can be bought and adjusted for organ playing.
Many dress shoes could be suited to playing the organ provided they have narrow toes and a somewhat elevated (preferably leather) heel that's not too narrow where it could slip off the pedal key.
Rubber or plastic heels and soles do not glide as well on the pedal keys.
Very few shoes are designed specifically for organ playing, but probably the best known product in the USA is Organmaster shoes.
Organmaster shoes (photo) are made by Capezio, a Connecticut based company, though they differ somewhat from the dance shoes this company also sells [See blog, Shoes, Part IV].
Organmaster shoes are very thin on the bottom for feeling the pedals through the soles, which also makes them vulnerable to wear if the player would decide to use them for general purpose walking; these need to be used for organ playing only ... and it's important to bear in mind that, for all of their advantages for playing the organ's pedals, Organmaster shoes make very poor street shoes, just as street shoes have an entirely different office to fill as general footwear.
The typical features of an acceptable organ shoe are 1) a flexible, lightweight leather or synthetic upper held snugly to the foot by a lace, strap, or ribbon; the material should allow the player's feet to glide against each other without sticking together, 2) a soft, flexible leather or suede sole that allows the player to slip the foot easily both up and down a pedal and across pedals; the sole should be thin enough to feel the pedals easily, and it should not extend beyond the sole of the foot, and 3) a slight heel of about an inch in height, wide enough so that it cannot become wedged between 2 pedals.
Some organists prefer a dance shoe or modified tuxedo shoe with a slightly shorter heel that they can also wear into and out of the building (a standard tuxedo shoe, for example, with heel built up 3/4 inch, was preferred by Virgil Fox); if the player can manage to keep dirt and grime off the pedal keys by wearing only one pair of shoes like this, then this would pose an advantage.
Many types of footwear, however, are unsuitable for pedaling; these include sandals, sneakers and other rubber soled shoes, flip flops, clogs, and any other shoe that fails to hug the heel, platform shoes, any other "chunky shoes," boots, or any other heavy or inflexible shoes that would slow or decrease the agility of the feet [See blog, A Third Hand], and men's "wing tip" dress shoes which have soles that project.
The elevated heel allows pedaling to become more deft because in rapid scale passages there is less ankle movement, heel to toe, and permits the heel and toe of the same foot to step across an intervening pedal key when playing thirds.
It's also important to remember, with shoes, that if we invest in a pair of organ shoes and think, by so doing, that all of our pedaling problems will be solved -- that may be a nice thought, but it's just an illusion.
It fails to explain how some performers have been known to perform very complicated counterpoint written into the pedal line, such as the Trio Sonatas of J.S. Bach, and perform these pieces well, in street shoes.
Some teachers would disagree with this premise, but the bottom line with organ shoes, when we consider all the facts objectively, has to be this: having a pair of shoes specially made for organ playing points us in a good direction especially when performing Romantic and post-Romantic repertoire which makes extensive use of the heels -- but the need for such a pair of shoes is not absolutely mandatory, particularly for those who perform Renaissance and Baroque organ repertoire almost exclusively where toes-only pedaling is considered stylistically accurate.
(con't in Part II)