The title of the song you guys are looking for is "All My Reasons" by Noel Pointer, 1981. It's one of my all-time favorites. I remember watching him perform in the Philippines way back when he was still alive. Other classic faves he played were Classy Lady, East St. Louise Melody, I Feel your Soul and Superwoman to name a few. He still remains my favorite violinist to this day.
You're right though. This was during the time of Earth, Wind and Fire's "After The Love is Gone" and "Fantasy", Kalapana's "Hurt" and "Nightbird", Ronnie Laws' "Stay Awake", Michael Franks' "Lady Wants to Know", Grover Washington, Jr.'s "Just The Two Of Us".
Those were the good old jazz days at the Rhythm and Booze in Greenhills. Good old days indeed.
Check out this link:
http://www.youtube.com/watch?v=ZqfyDfF1SOA