Aka white-tie: an ensemble that includes tails, wing-collared shirt, hand-tied white bow tie usually in a cotton pique or fine grosgrain, and corresponding white waistcoat, traditionally three buttoned and cut low to expose maximum shirt front. Trousers, striped. For the feet, nothing but glacé, glossy pumps will suffice, silk bows optional. This look was established as a sartorial must-do by the early 1920s.
Whether formal or extremely formal, the basic sonorous quality of the ensemble is the color black. As the costume historian James Laver in his massive The Concise History of Costume and Fashion (pdf here) pointed out, since the eighteenth century all attempts to introduce color to male formal attire have failed or have been derided. A shiny, colorful, patterned male evening ensemble is unthinkable; such is the continuing power and influence of tradition.
Read more historical notes on my book blog.