Cropper was the guitarist in Booker T's MGs. The 5 Royales were the '50s R&B group who first lit the Stax man's fuse as a kid.
Hence this suite of Pauling covers: generic period R&B appropriately reverenced by a socking rhythm section (Hood/Oldham/Ferrone/Jordan) and a toppish-notch raft of guests, including Bettye Lavette, BB King, Steve Winwood, Dan Penn, Buddy Miller, Sharon Jones, Lucinda Williams and, erm, Brian May. Cropper's Tele rings like a bell. Pretty lovable.