Delilah, the carefully crafted group of leggy, hot chicks, sang “Whataya Want from Me” made semi-famous by the great American Idol runner-up, Adam Lambert. I didn’t pick up on it last week, but this group is like a buncha snotty sorority girls. And they take themselves waaaaaay too seriously and that might be their downfall, eventually. They have great vocal talent. They have sex appeal to spare. For a girl group, they have a deep bass that can carry them, but they had better watch themselves about making every song so dreary and heart breaking. Eventually the sad, strained faces are going to be too depressing for a jaunty a capella show like The Sing-Off. Gimme some En Vogue, girls! Or some Spice Girls! Or some Pussycat Dolls? It’s OK. Your Moms will be OK with it.