Curtis

From the legendary film, The Blues Brothers, we learn the backstory of Jake and Elwood Blues and that it was Curtis (Cab Calloway) who helped them learn about the blues music scene when they were in the orphanage. A father figure of sorts, Curtis taught the brothers how to dress and play the music that they loved. In the film, he would sing "Minnie the Moocher," a song that Calloway made a hit in the 1930s. Since he played it while waiting for the Blues Brothers to arrive, we could argue that he was their opener and really should be in the main category, but we feel his role as their mentor trumps that.