Stars put on a great show on Friday night at the Barrymore, complete with multicolored lights, bubbles, and a keyboard kazoo. And guitarist and vocalist Amy Millan wore sequins, just like the last time I saw her. If I were a rock star, I would wear sequins every night. Seeing all of the beautiful young things in the audience in their carefully-selected concert clothes got me thinking about (what else?) fashion. Here are some rock star-worthy looks from three of my favorite style bloggers. I’d be happy to wear any of the following ensembles to a show. What the three looks have in common is that they all involve at…