Question about a portrait of Leonard Bernstein?

Hello, I am hoping someone out there can answer this:

In the National Portrait Gallery in Washington, D.C. there is a portrait of Leonard Bernstein. It is a painting of him when he was younger, and he is smoking a cigarette and possibly sitting at a piano. Has anyone seen the portrait I am talking about? I want to know who painted it. I saw it a year ago, and wrote down the artist's name, but I have since lost it. Also, if you are familiar with the portrait, would you happen to know where I can purchase a print of it?