Has R and B become a one trick Pony?

Now I was feeling nostalgiac and listening to probably the greatest and most pure voice in r and b ever, the one and only Luther Vandross. Now it wasn't just the voice that got me, it was his style and flair. We all know the rumors about Luther being gay but the moment he opened his mouth and started singing, you no longer cared anything about that, you just knew that something great was