As we can only expect, everything gets a little oversimplified. Little Richard's wavering between religion and rock 'n' roll was a lot longer and less resolved than we see here, his sexuality was more complex-- I should say "even" more complex-- and hey, Pat Boone was not a bad singer. He was entirely the wrong singer for Little Richard's music, and he's admitted it forthrightly more than once, but he wasn't the talentless dummy that's shown in this movie.
Review of Little Richard
