The great comic/compositional/instrumental/vocal genius who was Thomas “Fats” Waller has a catalogue of awesome breadth and depth, comprised of small combo, orchestra and solo piano and organ performances, all recorded in a 20-year span from 1923 to 1943 (when he succumbed to bronchial pneumonia a few months shy of his 40th birthday). —in toto, more than 400 tunes committed to disc. A gifted songwriter, whose frequent collaborator, lyricist Andy Razaf, was also one of the best of his time, Waller left behind American song monuments such as “Honeysuckle Rose” and, of course, “Ain’t Misbehavin,” and also proved himself a formidable interpreter of classic pop songs of the day, his stamp on tunes such as “(I’ll Be Glad When You’re Dead” You Rascal You,” “It’s a Sin To Tell a Lie” and “I’m Gonna Sit Right Down and Write Myself a Letter” so unmistakably Waller that it’s hard to believe he didn’t write those as well. In the mid-‘90s RCA did a great service to Waller and his legacy by issuing the heart of the artist’s oeuvre, that being the recordings he made between 1934 and 1943, in a five-volume, multi-disc (13 in all), superbly annotated collection titled Fats Waller and His Rhythm, which was also the name of one of his finest combos of that period. Those discs were allowed, unbelievably, to go out of print, but Bluebird/Legacy has stepped in to correct a wrong with “If You Gotta Ask, You Ain’t Got It,” a three-CD, 66-song overview of Waller’s art, arranged thematically as one volume of vocal performances (“Fats Waller Sings and Plays Fats Waller”), one of instrumentals only (“Strictly Instrumental”) and a third disc of Waller’s renderings of Great American Songbook entries (fancifully but tellingly titled “Fats Sings and Plays Around With Tin Pan Alley”). Volumes One and Three are largely showcases for the Fats Waller and His Rhythm combo and comprise the big man’s most enduring recordings, from the tender-hearted balladry of “A Hopeless Love Affair” to the wry discourse, “All That and No Potatoes,” with the coup de grace being the amazing version of “Ain’t Misbehavin’” recorded for the film Stormy Weather. The instrumental disc is a real treat, as it features three robust performances on pipe organ, including the Louisiana Sugar Babes’ graceful ode to the south, “’Sippi,” written by and featuring on piano the stride giant James P. Johnson (alas, Waller’s organ is barely audible on the track, a flaw in the original recording); and nine richly textured solo piano numbers that illustrate how Waller took Johnson’s stride style into new realms of expressiveness. Sixty-six tunes is barely scratching the surface of Waller’s rich art, but the smart selections, and the best sort of annotators-as-tour-guides in producer and Waller expert Orrin Keepnews and veteran jazz writer Dan Morgenstern, make this an essential, and most enlightening, celebration of an American original.