Used to be that R&B acts would cover mainstream pop hits routinely, often improving them in the process. You can’t find a better example than what the Isley Brothers did with this Seals and Crofts hit. They slowed it from mid-tempo to ballad, dressed it in Ron Isley’s passionate vocals and Ernie’s expressive electric guitar — check the two-minute solo that ends the song — and while the result didn’t top the charts, as the original did, it’s the one I’d rather listen to today.
For comparison, here’s the Seals and Crofts version.
And here’s a 1974 clip of the Isleys performing the song live on “Soul Train.”