After a successful first year, the month-long, multi-genre series of free shows, Jax River Jams, will return to Downtown Jacksonville’s Riverfront Plaza in April, with another bananas list of headliners including ’90s pop-rockers Spin Doctors, iconic vocal group Boyz II Men, country star Carly Pearce and Atlanta indie-rock darlings Manchester Orchestra. The announcement from the City of Jacksonville, Downtown Vision …