The dresses worn by the female cast members during "Don Juan Rehearsal" are incredibly detailed and luxurious, compared to how little stage time they have. This was designer Maria Bjørnson's will. She believed that if the wearer of the costume felt the rich materials and saw all the details, they would act accordingly - they would feel the elegance of a Parisian 19th century lady. Often these also substitute the civil-dressed Hannibal princess if there is a lack of the right size of that dress - and the Hannibal princess has also found her way into the Don Juan rehearsal scene.

I have only seen one of the design for the rehearsal ladies. I've called her "the elegant lady", I have no idea what she's called in the costume bible. This one wears a frock like dress with wide, hanging sleeves. Under sleeves of a contrasting material can be seen. The design suggests green and black nuances, but it has also been made in other shades. It often get a V shaped "bib" or collar in he neck/front, and she also wears an elegant veiled hat. This dress is based on a traveling suit from an 1887 edition of Harpers Bazaar (first photo).

Another recognizable dress is the "Polonaise", the outfit with an overdress draped so the skirt forms points in front, and a bustle in the back, worn over a contrasting bodice and skirt. This Victorian fashion was inspired by 18th century Polonaise dresses. This dress has long, narrow sleeves with pleated cuffs and a puff, and is often made of materials in purple, pink or rust shades. The underbodice is often pointed and sometimes with buttons in front, and it's also usually darker than the undesrkirt. On her head there's a wide-brimmed had with decorations.

The most typical dresses from the rehearsal scene are grey, silver or brown in nuances. They have a bodice and a skirt; the bodice is high-necked and without too much decorations, but is often pointed and with long sleeves and with some sort or collar in the neck or trim down front. The skirts often have a pleated layer with drapes on top, and a defined bustle shape. A hat with decorations and a well-dressed, curly wig is also essential. I don't know how many different designs exist for the Don Juan Rehearsal; based on the variants I would think 7 or 8. But I don't know for sure. As a side note, the Las Vegas production is the only one who didn't have the Don Juan Rehearsal scene, and hence they didn't have the costumes from that scene either.