The Sweet Inspirations were backup singers to a long list of major acts, most famously Elvis Presley, and including Wilson Pickett, Jimi Hendrix, Solomon Burke and Aretha Franklin. They can be heard on the Dusty Springfield classic album Dusty in Memphis, as well Van Morrison's "Brown Eyed Girl".
The Sweet Inspirations also had a few hits of their own in the late-60's. My favorite is "Sweet Inspiration" from 1968, written by Dan Penn and Spooner Oldham:
At this point the group consisted of Cissy (Drinkard) Houston, Estelle Brown, Myrna Smith and Sylvia Shernwell. Various other members came and went though the Sweet Inspirations long career, which started in the late 1950's. They continued recording through 2005, and have performed even more recently.
But the composition, musicianship and and most of all vocals on "Sweet Inspiration" are just perfect, a powerful love song.