Mercury Blues 'n' Rhythm Story 1945-55 is an eight-disc, 211-track collection covering Mercury's first decade as a label. Each of the four discs is arranged thematically according to region -- East Coast, West Coast, Midwest, and Southwest -- and each features a number of blues and R&B classics, including cuts from Professor Longhair, Johnny Otis, Eddie "Cleanhead" Vinson, Dinah Washington, Lightnin' Hopkins, Jimmy Witherspoon, and Big Bill Broonzy. 22 unreleased performances are mixed into the compilation, making the set enticing for collectors, but the main value of Mercury Blues 'n' Rhythm Story 1945-55 is as a concise overview of one of the most influential R&B labels in history. ~ Stephen Thomas Erlewine