The greatest compliment to Ann Marie Olson's performance in Thinking Cap Theatre's Always... Patsy Cline is that I forgot I was watching Ann Marie Olson. This is what it means to disappear completely within a character, in this case this doomed singer who brought Nashville country music into the pop mainstream before perishing in a plane crash at age 30. With very little dialogue, Olson captured Patsy Cline's exuberant spirit and fundamental kindness — but what's more impressive was her pitch-perfect mastery of 27 Cline songs, from hits like "Crazy" and "Wa kin' After Midnight" to the more-obscure selections that would fill four-hour set lists at forgotten '50s honky-tonks. They're all a far cry from the traditional Broadway vocal arrangements Olson has conquered for Slow Burn Theatre, yet they seemed as comfortable leaving Olson's lips as church hymns to a reverend. If there were ever a local production that deserved its own cast album, it's this one.