Jennifer Nettles, without Sugarland, and Brandy Clark at Lincoln Theatre

There is no Sugarland without Jennifer Nettles. So what is Jennifer Nettles without Sugarland? Nettles delivered the answer during the first concert of her first solo tour, which kicked off at the Lincoln Theatre on Valentine's Day: These are not the same energy-packed, carefree, delightfully weird days of her enormously successful country duo with Kristian Bush. The Jennifer Nettles solo era is calmer and more serious. The songs are slower and more thoughtful. The lyrics hit you harder.