In the "old" days it was pretty much required to be able to act, sing and dance. Some of the finest performers of all time could do it all. Judy Garland, Ethel Mirman, Bing Crosby, Frank Sinatra ... etc.
Today ... I'm not so sure. Christopher Walken can act and dance ... not so much in the singing department.
Natalie Portman is a good actress (I wouldn't say great) and she can rap (as seen on SNL).
I can't think of any modern actress/singers that knock my socks off. Madonna? Cher? Hardly modern.
<B>EDIT: Thanks, willravel, for pointing out that this person has posted the exact same message on several boards. This could be a low-tech viral marketing attempt to drive people to J. Landon's song ... if so, I'll bet it gets deleted soon. </b>