Who is John Mayer? He is just a young man in his late 20's who wants to sing good songs. But because Jessica Simpson is rumored to be going out with him his celebrity star is rising with celestial speed. John Mayer is a singer and songwriter who has done very well on his own up to now. He will do much better though, at least in the very near future, with Jessica on his wings. Here's a video clip of him singing "Come back to bed". It doesn't do much for me on first impression, but that's part of the mysterious beauty of personal chemistry and preferences.