Recorded and issued around Halloween in 1969, Soul Bag was the beginning of a shift for Willie Mitchell as a musician. His earlier records were steeped in soulful but also often turgid cover versions that barely deviated from the originals they served. His groove was much more laid-back than anything else recorded at Stax during the time. It's hard to say what motivated the change, but the Mitchell who entered the studio in September had different ideas about his own records. Soul Bag is an exuberant, mostly uptempo collection of covers and originals that reflects new interpretive powers by Mitchell as an arranger. On Sly Stone's "Everyday People," the Memphis rave-up groove replaces the funky singsong sound of the original. Led by Booker T.'s organ and Steve Cropper's guitar with a slew of horns as a chorus, the tune reaches the apex of slippery Southern soul very quickly and stays there. Likewise, Mitchell radically reinterpreted the theme from the television program Hawaii Five-0, turning it into a lounge jazzer with a deeper than blue saxophone line, while the Cropper/Eddie Floyd classic "Knock on Wood," with its rolling bassline and meat-and-potatoes saxophone line playing the lyric, offered a depth to the tune that singers would often miss. This is essential Willie Mitchell, from a period of transition that changed everything not only in the way he issued his own recordings, but in the way he produced others.