Sylvester: "I (Who Have Nothing)" 12-inch single, Fantasy D-129, released 1979. 

Of the Sylvester compilations I have encountered, I've never seen this track on any of them. It had a lot of local airplay when it was first released, but I didn't hear it at all past 1979. This is a double-A-side 12-inch single, with a longer version on one side (about 10 minutes) and shorter on the other (over 6 minutes).
Track List
----------------
I (Who Have Nothing) -- Long Version
I (Who Have Nothing) -- Short Version