What to KnowChristina Aguilera, Meek Mill, Jill Scott, Will Smith and more are set to perform on the Benjamin Franklin Parkway in Philadelphia on the 4th of July for the “One Philly: Unity Concert for America.”While gates were scheduled to open at 3 p.m., the gates did not open until around 4 p.m. The free concert began at 5 p.m. ET. You can watch the concert LIVE on NBC10.The full concert lineup includes Christina Aguilera, Meek Mill, Jill Scot…