COMPARE THE CHORUSES. In the first song, you'll hear it at around 0:30,
and in the second, around 1:20.
The songs differ in pitch by a half-step, the lyrics are different, the bass lines and chord changes are different -- but the chorus vocals are nearly identical harmonically and rhythmically.
The first song, from '82, was written by Joey Gallo and Kevin Spencer, produced by the great Leon Sylvers III, and sung by the sweet-voiced Carrie Lucas. Sylvers additionally wrote and produced hits for the Whispers, Shalamar, Lakeside, and Midnight Starr, all labelmates at LA's Solar Records (which was co-founded by Don Cornelius of Soul Train fame).
The second song, from '89, is credited to Gene Griffin and performed by Today. Production was by Griffin's protege, a then up-and-coming Harlem music wunderkind named Teddy Riley.
It should be noted that, aside from the chorus vocal parts, the songs are very different, right down to instrumentation and recording technique. "Show Me" is classic early '80s dance funk: all humans, no sequencers or drum machines; smart but simple drum pattern; everything perfectly in the pocket; the kind of bass line that makes you miss bass lines. The band is the same crack studio team that backed the Whispers on their biggest records.
"Girl," by contrast, features the patented synthesized, layered, drum-machined, stuttering-digital-sample- studded, driving and infectious sound that Riley invented and dubbed "New Jack Swing" -- the music I tried to do the "Running Man" to back in high school.
The two songs differ lyrically too. Whereas Griffin/Riley/Today are all about layin' down the mack and romancing their target, the original song is all about pre-AIDS-era frankness: don't bullshit me about romance when all we really want is to get down.