The Blues Brothers are an American blues and soul revue band founded in 1978 by comedians Dan Aykroyd and John Belushi, who met and began collaborating as original cast members of Saturday Night Live. A common misconception is that the act also originated on SNL. The Blues Brothers, however, was an independent project of Belushi and Aykroyd, first appearing as the opening act for comedian Steve Martin. Martin later appeared on Saturday Night Live as host, and the Blues Brothers appeared as the musical guest.
https://en.wikipedia.org/wiki/The_Blues_Brothers