Which Came First?

So today's (justly) over-hyped listicle is the "50 Greatest Hip-Hop Samples of All Time" as selected by two guys in Complex magazine.

I'm not here to quibble with the list -- it's worth your time to plow through and enjoy some slamming soul beats and a few back-stories along the way.  Instead, I was struck by hearing #10, a Kool and the Gang jam from 1969 that immediately had me scrambling for the single biggest punch-line used against me in college radio. My question: which band used this core riff first?

Kool & The Gang - Chocolate Buttermilk

Chicago Transit Authority - Beginnings

Seriously, spend a few hours poking through the originals and the sampled uses... a fantastic-ly old school way to start a weekend.