By Diana Powers, Contributor [RCA; 2016] Rating: 6.5/10 Key Tracks: “Need U,” “No Limit,” “Bump” Usher was once the king of R&B, embodying late 90’s/early 2000’s R&B with his buttery smooth voice. His classic hits such as “My Boo” and “U Got It Bad” have even come to define a whole time period of popular music. However,…