ABC’s Nashville is adding another heartthrob. The OC alum Chris Carmack is joining the soapy freshman drama as Will, a sexy and charming country singer and guitar player, the kind of guy men want to be friends with and women want to be with. Carmack will appear in six episodes this season, becoming a regular in Season 2. (ABC has not made renewals yet but Nashville is expected to get a pickup.) Carmack, repped by Innovative and Luber Roklin, has done extensive stage work on Broadway and in London.