From Buffalo Springfield to Poco to Loggins & Messina, Jim Messina has spent five decades at the center of American rock history. An evening at The Franklin Theatre with him is a rare chance to experience it all up close. The man who helped define country rock, accidentally formed one of rock’s most successful duos, and produced Rock & Roll Hall of Famers brings hits like “Your Mama Don’t Dance,” “Danny’s Song,” and “Angry Eyes” to a 300-seat room.