It rather depends on the level of formality. Not all black-tie events are equal. My preferred choice is a black velvet Sheriffmuir but I have also worn a black barathea Argyll. The PC from my younger days is now a wee bit tight. Temperature is also a factor and the desirability of keeping cool during reels can dictate the lightest jacket and no waistcoat. My recently purchased and refurbished Kenmore/Balmorral type doublet will get an outing later in the year.