I've been thinking about the SF Ballet recently and the elaborate yet etherial costumes the dancers wear. When I think about form and function, a ballet costume is a clothing design feat.
A ballerina needs to have a full range of movement while dancing in their costume. While at the same time, the costume is also an extension of that movement. The skirt moves at it's own pace, depending on fabric, and can enhance or exaggerate a leap or twirl.
An interesting fact about ballet shoes in the 17th century is that the dancers traditionally wore heeled shoes! Skirts were shortened to mid calf in the 18th century and the tutu became the traditional costume in the 19th century.