If you live in NYC area, and even if you don't bc she'll travel, Tara O'Grady and her Black Velvet Band are THE best band for your wedding. Classy, elegant, vintage, romantic, swinging, fun. And she sounds like Billie Holiday and Patsy Cline and Doris Day all wrapped into one. Perfect for cocktail hour, but they also can perform the entire night if your guests love to swing dance or feel like they are back in time (20s, 30s, 40s, 50s). She'll also learn new songs for you. Her band was featured on the TV show Four Weddings. Check out her site:
http://taraogradymusic.com/