Some may disagree but if a man needs only one set of evening clothes for the fall season I think the midnight blue four button double breasted dinner jacket with black grosgrain facings is the semi-formal style to choose.
All things being relative, the double breasted is the informal approach to black tie. Less stiff than its single breasted, waistcoated relation it looks good with either peak or shawl lapels and an unstarched pleated shirt with a turn-down collar. Woolen merchant H. Lesser offers a 12 ounce midnight blue barathea that's just about perfect for tycoons and those who wish to look like them.
The opera diva is an optional accessory that can add considerably to the evening experience.