Del The Funky Homosapien - No More Worries (1993) sampled Jerry Butler And Jerry Peters - Part III (1972)

Artist:  Del The Funky Homosapien
Song:  No More Worries
Year:  1993
Album:  No Need For Alarm

A good one-bar loop is hard to find, they can be repetitive.  Del has a good one here.  The track features A-Plus, Casual and Extra Prolific.

Artist:  Jerry Butler And Jerry Peters
Song:  Part III
Year:  1972
Album:  Melinda (Original Music From The Motion Picture) (Melinda OST)

The sample is the one-bar loop starting at 0:06.