"They're not going to catch us," Dan Aykroyd, as Elwood Blues, tells his brother Jake, played by John Belushi. "We're on a mission from God."

So opens the musical action comedy The Blues Brothers, which hit theaters on June 20, 1980. Their scripted mission was to save a local Chicago orphanage. But Aykroyd, who conceived and wrote much of the film, had a greater mission: to honor the then-seemingly forgotten tradition of rhythm and blues, some of whose greatest artists--Aretha Franklin, James Brown, John Lee Hooker, Cab Calloway, Ray Charles--made the film as unforgettable as its wild car chases.

Much delayed and vastly over budget, beset by mercurial and often drugged-out stars, The Blues Brothers opened to outraged reviews. However, in the forty-four years since, it has been acknowledged a classic. It has been inducted into the National Film Registry for its cultural significance, even declared a "Catholic classic" by the Church itself, and re-aired thousands of times on television to huge worldwide audiences. It is, undeniably, one of the most significant films of the twentieth century.

The story behind any classic is rich; the saga behind The Blues Brothers, as Daniel de Vis