Jim Belushi was left out by producers who thought they knew best.

The liner notes for Briefcase Full of Blues tells some of their story, including the fact that they only become blood-brothers when, at the orphanage, Jake takes a guitar string from Elmore James' guitar, slices open their middle fingers, and they touch them together:

Jake had a vision. It was his, the only real one he'd ever had, and he clung to it. There had been too many messy gas station holdups with only some green stamps and a case of Valvoline to show for the risk. Joliet Jake had always been full of schemes. But this was different; it played across his tiled cell wall 24 hours a day. And the ending was always the same – Jake and his younger brother Elwood cruising out of Calumet City, Ill., with the sun in their shades and a full tank of gas. He absentmindedly rubbed his Buddha belly; even on a diet of jail food and Chesterfields, Jake had gained weight. Someday they’d have a penthouse on Lake Shore Drive … float around with bourbons and blonds. It was out there for the taking and Jake could smell it like ozone in damp air.

It had always been the blues. Even back in the Rock Island City orphanage (that sweaty kid factory with the black windows) Jake and Elwood were saved by the music. actually, saved by a gray-haired janitor everybody called Curtis. He wore these sinister midnight shades, a narrow black tie and a porkpie hat that he kept pushed back on his head. Curtis wrapped his waxy brown hands around his guitar neck and played the most dangerous blues this side of Robert Johnson. The nuns scorched their days with holy threats and Curtis rescued them by night. Down in the coolness of his basement he taught the brothers the blues.

Silent Elwood never did put more than two sentences together, but all those lost words burned from his Special 20 blues harp. And Joliet tore that voice from some hidden darkness, twisting his chubby body, snarling at the heavens, a born sinner. They used the basement because it was secret and because the echo gave them a nice dirty sound: Howlin’ Wolf and Little Walker, slapping like a bad dream around the chilly room. and then one night, Jake brought in a gleaming E string he said came from Elmore James’ guitar. He held it tight and as it glowed in the bulb light, Jake sliced Elwood’s middle finger and then his own. Now the solo boys with soul in their blood were brothers. Jake and Elwood Blues … the Blues Brothers.

When Jake could keep himself out of jail, Elwood took off from the Taser factory and the brothers rode the state bare. They played everywhere: after-hours clubs, black-light bars. Word spread quietly across the steel belt about the two men in the porkpie hats who still played the blues. And soon other musicians crawled out of the night. The Colonel showed up in Decatur with his Telecaster and Duck. The Shiv, Mr. Fabulous, Blue Lou, Bones, Triple Scale, and crazy Getdwa strutted in one Saturday night. Finally, Guitar Murphy, bigger than life, joined up and they were set. One scary soul band as mean and righteous as a fist.