I first came to this song via the Jayhawks version, from Tomorrow the Green Grass. I knew it was a cover from the beginning, but either I never picked up on the fact that it was a Grand Funk composition or else I took note of Mark Farner's writing credit at first and then promptly forgot.
I initially considered the Jayhawks version as a candidate for Killer Covers, but in the end I decided that the only thing I prefer about the Jayhawks rendition is the vocals. Otherwise they don't add enough of their own to consider it a superior cover. Compare the two below and decide for yourself.
BONUS: The Jayhawks' version:
