There’s a scene in Joan Micklin Silver’s 1977 film “Between the Lines” where the staff of the Boston underground newspaper the Back Bay Mainline is gathered at a press party for Southside Johnny and the Asbury Jukes. “We’re havin’ a party!” Johnny Lyon proclaims. “Everybody’s swingin’!” He quotes an old Sam Cooke song that the Jukes adopted as a reliable part of their repertoire. “Keep those records playing.” Don’t stop the music. Out on the dance floor, Max Arloft (Jeff Goldblum), the Mainline’s rock critic, is having a blast, flanked by fun-loving girls.