You never heard these tracks sound like this before. But then maybe that's because these versions were never released before: an R&B stomper done as an anthem in the vein of Aretha's Think, an uptempo R&B heater transformed into a looser slice of southern funky soul and a rock n roll classic re-imagined as a New Orleans-style funky nugget.
Perhaps back in the day at Stax, Capitol or Federal, some producer hip to what James Brown and Dyke Arlester were doing, managed to coax artists back into the studio after hours for one more take. The drums became a bit heavier and more syncopated, the bass a bit chunkier, a section was lengthened here or there and maybe a faster (or slower) tempo tried out. But perhaps when the money men heard the results, they were too behind the curve to bet on the new sound and these funky versions got shelved.
Then again, maybe you're listening to Mako & Mr Bristow's Stank Soul Edits Vol. 4, the latest in a series of 45 edits intended to sound like alternate 'lost' studio takes rather than well edits.