There is plenty to like about ABC’s prime-time drama Nashville. The centerpiece, of course, is music. Actors Connie Britton (Rayna James), Hayden Panettiere (Juliette Barnes), Charles Esten (Deacon Clayborne), Clare Bowen (Scarlett O’Connor), Sam Palladino (Gunnar), and others actually perform the songs in the series backed by a host of ace studio players.