'The Playhouse' includes a group of minstrels as part of the opening dream sequence in which all the performers and the entire audience of a small vaudeville theatre are played by Buster Keaton. Though still not comfortable to watch, it's interesting to see that the extreme makeup was worn by the two comics, while the musicians only had their faces darkened a bit. I'm guessing this was the usual convention when Busby Berkeley was not involved. Even the in stills I've seen from Bert Williams' 'Lime Kiln Field Day,' in which all the actors really are African-American, he, as the comedy lead, is in a more subdued version of his vaudeville stage makeup while everyone else looks normal.