I have been looking for a three book series for many years, but I can not remember the titles, or author. All I remember is it was set in space, in military type service, and the main character had a unique two-tone whistling and the name Gershwin ( which I think was the music he whistled). And the Earth was a wasteland, yet the main character was found there as a boy and raised in the service. I want to find and purchase this series. I read it many years ago, but have never seen it since. Does this sound familiar to anyone?