Music takes center stage in Boston this weekend, with something for nearly every taste. ABBA fans can revisit the hits by candlelight, while jazz lovers can gather for a free, all-ages festival at the Hatch Shell. Hip-hop pioneer Rakim brings decades of influence to City Winery, and J. Cole headlines TD Garden with "The Fall-Off Tour." Although the festival is free, the Boston Jazz Foundation encourages registration and donations to support musicians and keep the event accessible. Other EventsThe Boston events this weekend highlight hip-hop as J. Cole brings "The Fall-Off Tour" to TD Garden.