Django and Jimmie (2 Lp's)Willie Nelson and Merle Haggard first teamed up on record for Pancho & Lefty in 1983, a record released some 20 years after both singers began their careers. Back then, they were both hovering around 50, already considered old guys, but Django and Jimmie arrives 32 years after that record, when there's no question that the pair are old timers. Appropriately enough, mortality is on their minds throughout Django and Jimmie, a record whose very title is