I have never heard Luther Vandross hit a sour note. He was a first class vocalist, talented writer, excellent producer and great duet partner. He could just straight sing. There were no need for a million runs and rifts because he was comfortable with his voice. His stage presence with that voice made him one of Gods greatest talents to ever walk the earth. Luther is what you call a singers singer. Meaning Luther Vandross is your favorite singer, favorite singer.
Luther Vandross - A House Is Not A Home