Choose your clothes depending on the protocol of the event in which you plan to attend. Each level of formality has its own code and rules (its protocol) that attendees are expected to follow. The more formal the dance, the more formal the outfit. For example, at a charity ball, anything less than a tuxedo or ball gown is consider a major faux pas. If you want to join and enjoy, it is smart to show respect for the customs of each dance.

Here are some of the dress codes you are likely to encounter :

White Tie : The most formal catagory of dress. Also called "cravate blanche" or "full evening dress."
Gentlemen:  Black trousers trimmed by two lines of braid (silk stripes) on the outside of each leg. A matchining black tailcoat. A white pique tie on a wing-collar shirt with a stiff pique front. A white pique single or double brested vest. White gloves are often worn. Patent black shoes (either pumps with a black silk bow, or closed laced oxfords). Suspenders, never wear a belt. Top hats are now optional.
Ladies:  Ball gown (an evening dress with a full skirt, possibly with open back and low neck line). Elbow-length gloves.

Black Tie
Gentlemen: Tuxedo coat and black trousers. The leg of the trousers are trimmed with a single braid (a satin stripe). Cumberband and a bow tie. The tie can, and often is, of any color as long as the cumberband matches, but black is preferred. However, never wear a white tie to a black tie event -- white ties are reserved for tailcoats only. White dress shirt with french cuffs. The tuxedo coat is black in most cases except for open-air evening parties or on cruises. Patent black shoes (either pumps with a black silk bow, or closed laced oxfords).
Ladies: Ball gowns

Black Tie Optional
Gentlemen: Same as "black tie," or wear a regular suit with a tie. Bow tie is preferred.
Ladies: Cocktail gown or dinner dress (long to full-length skirts).

Formal
Gentlemen: Suit and tie
Ladies: Cocktail gown or evening dress

Semi-Formal: Applies to all dances that are not formal, black tie, nor white tie events and are not labeled as informal.
Gentlemen: Dress slacks. Button up dress shirt. Tie. (Options: Jacket; Vest. The least formal of these do not require a tie. No khakis!)
Ladies: Evening dress, dinner dress, or flowing pants.

Informal : Applies to practice dances, workshops, and "dance lesson only" classes.
Gentlemen: Dress for comfort, but stay away from shorts, tank tops, and sneakers. Solid T-shirts (as opposed to print T-shirts). Cotton slacks.
Ladies: Dress for comfort, but stay away from shorts, tank tops, and sneakers. Use your imagination and sense of fashion. Don't forget the dance shoes.

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