Organist Bruce Katz gets lowdown and greasy on Mississippi Moan (Audioquest 1047; 56:41), his third as a leader. A longtime sideman to guitarist Ronnie Earl in the Broadcasters, Katz cooks up a brilliant marriage of blues, jazz, gospel and soul on both piano and Hammond B-3. “Hep-ology” is a rockin’ shuffle highlighting Katz’s humming B-3 in sleazy dialogue with Tom Hall’s growling tenor sax and Mike Costello’s raunchy Chicago-styled harmonica. The lilting New Orleans rumba “Night Of Joy” shows a decided Professor Longhair influence, with a few Monkish twists thrown in. Deep blues vocalist Mighty Sam McClain guests on the slow blues “Hanging On The Cross,” which also features some appropriately soul-drenched guitar responses from Julien Kasper. Katz pumps the piano like a combination of Jerry Lee Lewis and Albert Ammons on a rollicking “Norton’s Boogie.” A heavy gospel vibe permeates the title track and “In The Garden” before they jump back on the jump blues bandwagon with an exhilarating “Elmore’s Glue.” They put an inventive, funky twist on an instrumental rendition of the Les McCann-Eddie Harris classic, “Compared To What,” and they take it out in sanctified fashion with the suite-like “Praise House.” Like Katz’s 1993 Alligator debut, Crescent Crawl, and his 1994 Audioquest debut, Transformation, this one showcases a talented musician brimming with ideas about how blues, jazz, gospel and soul relate. He provides some intriguing bridges for listeners on Mississippi Moan.