Rock stardom on a shaky foundation

Irish director John Carney has created a filmography rooted in his love for music. Carney's first hit, Once, reached screens in 2007 with a story about two unlikely partners who made music together. Carney, who followed with other films that fit his mold, now delivers Power Ballad, which feels familiar but dips its toe into the world of rock stardom. Paul Rudd plays Rick Powers, a once rising rock star who settled in Ireland, married Rachel (Marcella Plunkett), and raised a daughter (Beth Fallon) who's now a teenager. As his dreams of stardom faded, Rick supported himself as a singer and guitarist with Bride and Groove, a band that specializes in wedding parties. Bride and Grove works from a popular hit list, doing energetic covers of songs meant to keep a dance floor hopping. On one such gig, Rick meets Danny Wilson (Nick Jonas), a young singer who made it big with a boy band and who's trying to launch a solo career. Danny happens to be a guest at the wedding, and Rick and Danny…