Two of New Jersey’s premier performing arts groups proved this weekend that classical music can put a spotlight on both joy and justice. First was the New Jersey Symphony’s presentation of “Aretha: A Tribute,” an homage to Aretha Franklin, a late addition to the season. An eclectic mash-up of pop, gospel and Motown, the well-attended concert at the New Jersey Performing Arts Center drew a well-dressed crowd Saturday night in Newark that relished the sounds of the “Queen of Soul” as well as her 1960s and ’70s contemporaries and collaborators.