Rebecca Lynn Howard seemed to have found the breakthrough she deserved with 2002’s hit “Forgive,” but the failure of its follow-up singles initiated several years of record-label wrangling that kept her out of commission. Finally we have her third album in hand, and it’s clear that during the hiatus she’s been expanding her stylistic boundaries—No Rules sports several soul and R&B cover versions, and many of Rebecca Lynn’s original songs are rooted in that territory as well. It’s a framework that shows off her tremendous voice to great effect, and makes it tempting to wonder what we’ve missed out on for the last six years.