It didn't take long for Mercury Records -- the first label to be based in Chicago, IL -- to expand beyond the Windy City and its immediate environs, as evidenced by the beaucoup of soul-stirring delights in the second of four installments in the Mercury Blues 'n' Rhythm Story 1945-55 series. The two volumes in the "Southwest Blues" edition reach into the fertile rural regions, topographically stretching from Arkansas and into Creole country through to the Gulf Coast of Texas and all points in between. The copious contents (51 tracks in all) help to chronicle the formative styles being developed and compounded from origins as disparate as Delta blues and the subtle strains of West Indies calypso, which was wafting into the bayou via artists such as Roy Byrd (aka Professor Longhair). An ample nine selections from Roy Byrd & His Blues Jumpers are offered, with the seminal "Byrd's Blues," "Her Mind Is Gone," "Longhair Stomp," and "Between the Day and Night" (aka "Wee Wee Hours") from two sessions in the summer of 1949. Pianist Jay McShann was similarly influential in the rich Kansas City scene that would yield the likes of Charlie Parker and Jimmy Witherspoon, both of whom served in McShann's assorted combos. A June 1947 get-together with Walter Brown as well as a July 1945 confab with two additional singers -- Witherspoon and Crown Prince Waterford -- lead off this double-disc entry. The collection returns to the Big Easy for a pair of dates starring the irrepressible Alma "The Lollipop Mama" Mondy backed by bassist George Miller & His Mid-Driffs, one of whom was an up-and-coming musician named Dave Bartholomew. On these platters he plays trumpet; however, within a decade he'd become a primary force behind the so-called "big beat" of New Orleans. His arrangements and production skills helped redefine the Crescent City sound of Fats Domino, Allen Toussaint, Lloyd Price, Earl King, and countless others. No less essential are the stark and revealing Lightnin' Hopkins sides. Hopkins on guitar and vocals is joined by bassist Donald Cooks for a trio of studio confabs from July and September of 1951 and January of 1952, respectively. The results included "She's Almost Dead," "Crazy 'Bout My Baby," and the protest blues "Sad News from Korea." Collectors and connoisseurs should also avail themselves of equally worthy inclusions from Little Joe Gaines, Lee Graves, Violet Hall, Luther Stoneham, Smokey Hogg/John Hogg, and Elmore "Elmo" Nixon.