DJs and formality

The recent thread about black tie weddings raises a point I honestly hadn't even thought about, which is the formality of a DJ vs live music.As a bit of background, our wedding is late in the evening in NYC and will have a four course plated meal, where the entree is ordered at the table. Our ceremony is in the same space and cocktail hour will have a full open par, butlered apps, etc. We said on our website that suggested attire is "cocktail/black tie optional" and are perfectly happy for people to show up however they are comfortable but wanted to signal that bridal party and family will be in black tie attire and that guests are welcome to dress up if they want. So I don't take this to be a hugely formal event but does it seem too formal for a DJ? (I know we can do whatever we want but I'm looking for a gut check on peoples' expectations). We will have live music for the ceremony but planned to switch to a dj for the cocktail hour and reception. via /r/weddingplanning http://ift.tt/2u9BmnK