"Blue Eyes Crying in the Rain" was Willie Nelson's first Number One as a singer. Patsy Cline's version of Nelson's "Crazy" is on the Library of Congress's National Recording Registry. And "On the Road Again" ranks as the quintessential traveling sing-along, played everywhere from bars to ballparks. Even casual fans know those songs by the Red Headed Stranger. But dig deeper and there's a whole other Willie to discover. Here are 20 obscure, but no less great, tracks that help shine a light on the full Nelson.