2021 introduction: In celebration of the anniversary of his 70th birthday, we revisit this interview, the first of what would be many that (then-future SoulMusic.com founder) David Nathan conduced over almost thirty years with Luther Vandross, emerging as an in-demand jingle and background session singer and coincidentally a neighbor of David's on W. 56th St. in Manhattan at the time the quintet known as Luther which he had created released their 1st single for Cotillion Records…